diff --git a/packages/deploy-script-support/test/unitTests/test-startInstance.js b/packages/deploy-script-support/test/unitTests/test-startInstance.js
index 43059473921..fd048dcb50f 100644
--- a/packages/deploy-script-support/test/unitTests/test-startInstance.js
+++ b/packages/deploy-script-support/test/unitTests/test-startInstance.js
@@ -35,6 +35,8 @@ test('startInstance', async t => {
   const zoeInvitationIssuer = E(zoe).getInvitationIssuer();
   const zoeInvitationPurse = E(zoeInvitationIssuer).makeEmptyPurse();
 
+  /** @type {import('../../src/startInstance.js').IssuerManager} */
+  // @ts-expect-error cast mock
   const issuerManager = {
     get: petname => {
       if (petname === MOOLA_BRAND_PETNAME) {
@@ -47,10 +49,15 @@ test('startInstance', async t => {
     },
   };
 
+  /** @type {Petname=} */
   let addedPetname;
 
+  /** @type {import('../../src/startInstance.js').InstanceManager} */
+  // @ts-expect-error cast mock
   const instanceManager = {
-    add: (petname, _instance) => (addedPetname = petname),
+    add: async (petname, _instance) => {
+      addedPetname = petname;
+    },
   };
 
   const startInstance = makeStartInstance(
diff --git a/packages/run-protocol/src/proposals/econ-behaviors.js b/packages/run-protocol/src/proposals/econ-behaviors.js
index b9896c8ed71..501fd24a654 100644
--- a/packages/run-protocol/src/proposals/econ-behaviors.js
+++ b/packages/run-protocol/src/proposals/econ-behaviors.js
@@ -601,7 +601,7 @@ export const startRewardDistributor = async ({
       brand: centralBrand,
     })
     .catch(e => {
-      console.log('Cannot create fee collector deposit facet', e);
+      console.error('Cannot create fee collector deposit facet', e);
       return undefined;
     });
 
diff --git a/packages/run-protocol/src/runStake/runStakeManager.js b/packages/run-protocol/src/runStake/runStakeManager.js
index ba7cf8d3505..d4a2c70558d 100644
--- a/packages/run-protocol/src/runStake/runStakeManager.js
+++ b/packages/run-protocol/src/runStake/runStakeManager.js
@@ -6,7 +6,7 @@ import { makeRatio } from '@agoric/zoe/src/contractSupport/ratio.js';
 import { fit, getCopyBagEntries, M } from '@agoric/store';
 import { makeNotifierKit, observeNotifier } from '@agoric/notifier';
 import { E } from '@endo/far';
-import { defineKindMulti, partialAssign } from '@agoric/vat-data';
+import { defineKindMulti } from '@agoric/vat-data';
 import { makeTracer } from '../makeTracer.js';
 import { chargeInterest } from '../interest.js';
 import { ManagerKW as KW } from './constants.js';
@@ -162,7 +162,9 @@ const helper = {
       },
       updateTime,
     );
-    partialAssign(state, changes);
+    state.compoundedInterest = changes.compoundedInterest;
+    state.latestInterestUpdate = changes.latestInterestUpdate;
+    state.totalDebt = changes.totalDebt;
 
     const payload = harden({
       compoundedInterest: state.compoundedInterest,
diff --git a/packages/run-protocol/src/vaultFactory/liquidation.js b/packages/run-protocol/src/vaultFactory/liquidation.js
index cd92db128ff..b3089d7605c 100644
--- a/packages/run-protocol/src/vaultFactory/liquidation.js
+++ b/packages/run-protocol/src/vaultFactory/liquidation.js
@@ -8,25 +8,6 @@ import { makeTracer } from '../makeTracer.js';
 
 const trace = makeTracer('LIQ', false);
 
-/**
- *
- * @param {Amount<'nat'>} debt
- * @param {Amount<'nat'>} proceeds
- */
-const discrepancy = (debt, proceeds) => {
-  if (AmountMath.isGTE(debt, proceeds)) {
-    return {
-      overage: AmountMath.makeEmptyFromAmount(debt),
-      shortfall: AmountMath.subtract(debt, proceeds),
-    };
-  } else {
-    return {
-      overage: AmountMath.subtract(proceeds, debt),
-      shortfall: AmountMath.makeEmptyFromAmount(debt),
-    };
-  }
-};
-
 /**
  * Liquidates a Vault, using the strategy to parameterize the particular
  * contract being used. The strategy provides a KeywordMapping and proposal
@@ -86,7 +67,15 @@ const liquidate = async (
   ]);
   // NB: all the proceeds from AMM sale are on the vault seat instead of a staging seat
 
-  const { shortfall, overage } = discrepancy(debt, proceeds.RUN);
+  const [overage, shortfall] = AmountMath.isGTE(debt, proceeds.RUN)
+    ? [
+        AmountMath.makeEmptyFromAmount(debt),
+        AmountMath.subtract(debt, proceeds.RUN),
+      ]
+    : [
+        AmountMath.subtract(proceeds.RUN, debt),
+        AmountMath.makeEmptyFromAmount(debt),
+      ];
 
   const runToBurn = AmountMath.min(proceeds.RUN, debt);
   trace('before burn', { debt, proceeds, overage, shortfall, runToBurn });
diff --git a/packages/run-protocol/src/vaultFactory/prioritizedVaults.js b/packages/run-protocol/src/vaultFactory/prioritizedVaults.js
index 7fb472c6b31..43a2228dbd5 100644
--- a/packages/run-protocol/src/vaultFactory/prioritizedVaults.js
+++ b/packages/run-protocol/src/vaultFactory/prioritizedVaults.js
@@ -8,6 +8,9 @@ import { Far } from '@endo/marshal';
 import { keyEQ, keyLT } from '@agoric/store';
 import { makeOrderedVaultStore } from './orderedVaultStore.js';
 import { toVaultKey } from './storeUtils.js';
+import { makeTracer } from '../makeTracer.js';
+
+const trace = makeTracer('PV');
 
 /** @typedef {import('./vault').Vault} Vault */
 
@@ -99,7 +102,7 @@ export const makePrioritizedVaults = (reschedulePriceCheck = () => {}) => {
     // don't call reschedulePriceCheck, but do reset the highest.
     // This could be expensive if we delete individual entries in
     // order. Will know once we have perf data.
-    console.log('removeVault', firstKey, key);
+    trace('removeVault', firstKey, key);
     if (keyEQ(key, firstKey)) {
       const [secondKey] = vaults.keys();
       firstKey = secondKey;
@@ -125,7 +128,7 @@ export const makePrioritizedVaults = (reschedulePriceCheck = () => {}) => {
    */
   const addVault = (vaultId, vault) => {
     const key = vaults.addVault(vaultId, vault);
-    console.log('addVault', firstKey, key);
+    trace('addVault', firstKey, key);
     if (!firstKey || keyLT(key, firstKey)) {
       firstKey = key;
       reschedulePriceCheck();
diff --git a/packages/run-protocol/src/vaultFactory/vaultManager.js b/packages/run-protocol/src/vaultFactory/vaultManager.js
index 8b54142aeb1..ca07a14eb01 100644
--- a/packages/run-protocol/src/vaultFactory/vaultManager.js
+++ b/packages/run-protocol/src/vaultFactory/vaultManager.js
@@ -21,7 +21,7 @@ import {
 } from '@agoric/notifier';
 import { AmountMath } from '@agoric/ertp';
 
-import { defineKindMulti, partialAssign, pickFacet } from '@agoric/vat-data';
+import { defineKindMulti, pickFacet } from '@agoric/vat-data';
 import { makeVault } from './vault.js';
 import { makePrioritizedVaults } from './prioritizedVaults.js';
 import { liquidate } from './liquidation.js';
@@ -232,7 +232,7 @@ const helperBehavior = {
 
     // Update state with the results of charging interest
 
-    const stateUpdates = chargeInterest(
+    const changes = chargeInterest(
       {
         mint: state.debtMint,
         mintAndReallocateWithFee: state.factoryPowers.mintAndReallocate,
@@ -255,7 +255,11 @@ const helperBehavior = {
       },
       updateTime,
     );
-    partialAssign(state, stateUpdates);
+
+    state.compoundedInterest = changes.compoundedInterest;
+    state.latestInterestUpdate = changes.latestInterestUpdate;
+    state.totalDebt = changes.totalDebt;
+
     facets.helper.assetNotify();
     trace('chargeAllVaults complete');
     facets.helper.reschedulePriceCheck();
@@ -326,7 +330,7 @@ const helperBehavior = {
       // eslint-disable-next-line consistent-return
       return facets.helper
         .processLiquidations()
-        .catch(e => console.log('Liquidator failed', e))
+        .catch(e => console.error('Liquidator failed', e))
         .finally(() => {
           liquidationInProgress = false;
         });
@@ -426,7 +430,6 @@ const helperBehavior = {
       factoryPowers.getGovernedParams().getLiquidationPenalty(),
     )
       .then(accounting => {
-        console.log('liquidateAndRemove accounting', accounting);
         state.totalProceedsReceived = AmountMath.add(
           state.totalProceedsReceived,
           accounting.proceeds,
diff --git a/packages/run-protocol/test/supports.js b/packages/run-protocol/test/supports.js
index c10b401f477..b5a5fb2c0f7 100644
--- a/packages/run-protocol/test/supports.js
+++ b/packages/run-protocol/test/supports.js
@@ -14,6 +14,7 @@ import { makeFakeVatAdmin } from '@agoric/zoe/tools/fakeVatAdmin.js';
 import buildManualTimer from '@agoric/zoe/tools/manualTimer.js';
 import { makeLoopback } from '@endo/captp';
 import { E } from '@endo/far';
+import { makeTracer } from '../src/makeTracer.js';
 
 /**
  * @param {*} t
@@ -60,7 +61,8 @@ export const setUpZoeForTest = (setJig = () => {}) => {
 harden(setUpZoeForTest);
 
 export const setupBootstrap = (t, optTimer = undefined) => {
-  const space = /** @type {any} */ (makePromiseSpace(t.log));
+  const trace = makeTracer('PromiseSpace');
+  const space = /** @type {any} */ (makePromiseSpace(trace));
   const { produce, consume } =
     /** @type { import('../src/proposals/econ-behaviors.js').EconomyBootstrapPowers & BootstrapPowers } */ (
       space
diff --git a/packages/zoe/src/zoeService/zoe.js b/packages/zoe/src/zoeService/zoe.js
index 623bd3b4812..c7d87abfdeb 100644
--- a/packages/zoe/src/zoeService/zoe.js
+++ b/packages/zoe/src/zoeService/zoe.js
@@ -168,3 +168,6 @@ const makeZoeKit = (
 };
 
 export { makeZoeKit };
+/**
+ * @typedef {ReturnType<typeof makeZoeKit>} ZoeKit
+ */