2 questions about new/old previews and subscription feed video limit

[D0PHEP-bot]

1: can you disable "new preview" but leave the "old preview"?
new preview (on home page) acts like a mini player with subtitle/mute audio buttons (removing "watch later" on screen, but the "3-dots" menu button can load up slowly)

old preview still works on the channel's videos page

2: can you limit the amount of videos being loaded when opening a subscription feed?
it loads like 100 or more videos and wont show anything until its done loading the video feed