diff --git a/Cargo.lock b/Cargo.lock
index 8a8099bc6d98..2223ffdab7df 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -323,18 +323,18 @@ checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "serde"
-version = "1.0.147"
+version = "1.0.148"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d193d69bae983fc11a79df82342761dfbf28a99fc8d203dca4c3c1b590948965"
+checksum = "e53f64bb4ba0191d6d0676e1b141ca55047d83b74f5607e6d8eb88126c52c2dc"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.147"
+version = "1.0.148"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4f1d362ca8fc9c3e3a7484440752472d68a6caa98f1ab81d99b5dfe517cec852"
+checksum = "a55492425aa53521babf6137309e7d34c20bbfbbfcfe2c7f3a047fd1f6b92c0c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -366,9 +366,9 @@ checksum = "6bdef32e8150c2a081110b42772ffe7d7c9032b606bc226c8260fd97e0976601"
 
 [[package]]
 name = "syn"
-version = "1.0.102"
+version = "1.0.104"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fcd952facd492f9be3ef0d0b7032a6e442ee9b361d4acc2b1d0c4aaa5f613a1"
+checksum = "4ae548ec36cf198c0ef7710d3c230987c2d6d7bd98ad6edc0274462724c585ce"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/synapse/appservice/api.py b/synapse/appservice/api.py
index 60774b240d9f..11c5b10c9546 100644
--- a/synapse/appservice/api.py
+++ b/synapse/appservice/api.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+import time
 import urllib.parse
 from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Mapping, Optional, Tuple
 
@@ -324,6 +325,10 @@ async def push_bulk(
                     "left": list(device_list_summary.left),
                 }
 
+        if len(serialized_events) == 0 and len(ephemeral) == 0:
+            logger.info("Returning early on transaction: no events to send")
+            return True
+
         try:
             await self.put_json(
                 uri=uri,
@@ -365,7 +370,19 @@ async def push_bulk(
     def _serialize(
         self, service: "ApplicationService", events: Iterable[EventBase]
     ) -> List[JsonDict]:
+        new_events = []
         time_now = self.clock.time_msec()
+
+        for event in events:
+            if int(round(time.time() * 1000)) - event.origin_server_ts > (15 * 60 * 1000):
+                logger.warning("Dropping event (due to age) %s" % event.event_id)
+                continue
+            if service.id != "github" and service.is_interested_in_user(event.sender) and event.sender.endswith(":t2bot.io"):
+                logger.warning("Dropping event (due to echo) %s" % event.event_id)
+                continue
+            logger.info("Allowing @ fallback: %s" % event.event_id)
+            new_events.append(event)
+
         return [
             serialize_event(
                 e,
@@ -384,5 +401,5 @@ def _serialize(
                     ),
                 ),
             )
-            for e in events
+            for e in new_events
         ]
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index c4c0bc7315b4..2402bbbc9ba5 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -369,7 +369,7 @@ async def get_pdu(
         destinations: Collection[str],
         event_id: str,
         room_version: RoomVersion,
-        timeout: Optional[int] = None,
+        timeout: Optional[int] = 15000,
     ) -> Optional[PulledPduInfo]:
         """Requests the PDU with given origin and ID from the remote home
         servers.
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index bb20af6e91ed..1b4cfc89d9b0 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -87,7 +87,7 @@
 
 # when processing incoming transactions, we try to handle multiple rooms in
 # parallel, up to this limit.
-TRANSACTION_CONCURRENCY_LIMIT = 10
+TRANSACTION_CONCURRENCY_LIMIT = 50  # T2B: Raise from 10
 
 logger = logging.getLogger(__name__)
 
diff --git a/synapse/federation/sender/__init__.py b/synapse/federation/sender/__init__.py
index 3ad483efe079..a58cca4f826f 100644
--- a/synapse/federation/sender/__init__.py
+++ b/synapse/federation/sender/__init__.py
@@ -705,6 +705,11 @@ def send_presence_to_destinations(
         for destination in destinations:
             if destination == self.server_name:
                 continue
+
+            # T2B: Skip sending presence to servers we know don't support it
+            if destination == "matrix.org":
+                continue
+
             if not self._federation_shard_config.should_handle(
                 self._instance_name, destination
             ):
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index cd39d4d1113a..74d6897aa8ea 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -106,7 +106,7 @@ async def get_room_state(
         )
 
     async def get_event(
-        self, destination: str, event_id: str, timeout: Optional[int] = None
+        self, destination: str, event_id: str, timeout: Optional[int] = 15000
     ) -> JsonDict:
         """Requests the pdu with give id and origin from the given server.
 
diff --git a/synapse/federation/transport/server/federation.py b/synapse/federation/transport/server/federation.py
index 205fd16daa98..4e2d1b2331fa 100644
--- a/synapse/federation/transport/server/federation.py
+++ b/synapse/federation/transport/server/federation.py
@@ -100,14 +100,32 @@ async def on_PUT(
 
             logger.debug("Decoded %s: %s", transaction_id, str(transaction_data))
 
+            edus_before_filter = len(transaction_data.get("edus", []))
+
+            filtered_edus = []
+            for edu in transaction_data.get("edus", []):
+                edu_type = edu.get('edu_type', 'io.t2bot.ignored')
+                if edu_type == 'io.t2bot.ignored':
+                    continue
+                if edu_type == 'm.presence':
+                    continue
+                if edu_type == 'm.receipt':
+                    continue
+                if edu_type == 'm.typing':
+                    continue
+                filtered_edus.append(edu)
+
             logger.info(
-                "Received txn %s from %s. (PDUs: %d, EDUs: %d)",
+                "Received txn %s from %s. (PDUs: %d, Accepted EDUs: %d, Ignored EDUs: %d)",
                 transaction_id,
                 origin,
                 len(transaction_data.get("pdus", [])),
-                len(transaction_data.get("edus", [])),
+                len(filtered_edus),
+                edus_before_filter - len(filtered_edus),
             )
 
+            transaction_data["edus"] = filtered_edus
+
             if issue_8631_logger.isEnabledFor(logging.DEBUG):
                 DEVICE_UPDATE_EDUS = [
                     EduTypes.DEVICE_LIST_UPDATE,
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py
index f7223b03c364..b8c9080f447c 100644
--- a/synapse/handlers/federation_event.py
+++ b/synapse/handlers/federation_event.py
@@ -2151,7 +2151,7 @@ async def _run_push_actions_and_persist_event(
         # persist_events_and_notify directly.)
         assert not event.internal_metadata.outlier
 
-        if not backfilled and not context.rejected:
+        if False and not backfilled and not context.rejected:
             min_depth = await self._store.get_min_depth(event.room_id)
             if min_depth is None or min_depth > event.depth:
                 # XXX richvdh 2021/10/07: I don't really understand what this
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 4cf593cfdcbc..ff4f1c1b2a0b 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -1462,9 +1462,10 @@ async def _persist_events(
             a room that has been un-partial stated.
         """
 
-        await self._bulk_push_rule_evaluator.action_for_events_by_user(
-            events_and_context
-        )
+        # T2B: Disable push processing.
+        #await self._bulk_push_rule_evaluator.action_for_events_by_user(
+        #    events_and_context
+        #)
 
         try:
             # If we're a worker we need to hit out to the master.
diff --git a/synapse/handlers/user_directory.py b/synapse/handlers/user_directory.py
index 3610b6bf785e..bdda5e2f0f6e 100644
--- a/synapse/handlers/user_directory.py
+++ b/synapse/handlers/user_directory.py
@@ -70,7 +70,8 @@ def __init__(self, hs: "HomeServer"):
         # Guard to ensure we only process deltas one at a time
         self._is_processing = False
 
-        if self.update_user_directory:
+        # T2B: Disable user directory
+        if self.update_user_directory and False:
             self.notifier.add_replication_callback(self.notify_new_event)
 
             # We kick this off so that we don't have to wait for a change before
@@ -109,6 +110,11 @@ async def search_users(
 
     def notify_new_event(self) -> None:
         """Called when there may be more deltas to process"""
+
+        # T2B: Disable user directory
+        if True:
+            return
+
         if not self.update_user_directory:
             return
 
@@ -133,6 +139,10 @@ async def handle_local_profile_change(
         # FIXME(#3714): We should probably do this in the same worker as all
         # the other changes.
 
+        # T2B: Disable user directory
+        if True:
+            return
+
         if await self.store.should_include_local_user_in_dir(user_id):
             await self.store.update_profile_in_user_dir(
                 user_id, profile.display_name, profile.avatar_url
@@ -142,6 +152,11 @@ async def handle_local_user_deactivated(self, user_id: str) -> None:
         """Called when a user ID is deactivated"""
         # FIXME(#3714): We should probably do this in the same worker as all
         # the other changes.
+
+        # T2B: Disable user directory
+        if True:
+            return
+
         await self.store.remove_from_user_dir(user_id)
 
     async def _unsafe_process(self) -> None: