Blocking a community from a post’s … menu causes the timeline to refresh. This only happens when blocking directly from the timeline, not from within the post. It also kind of happens when blocking from a community’s page, refreshing that community’s timeline but not the main timeline. The refreshing can be frustrating because it takes you back to the top of the timeline and you have to scroll all the way back to where you were.
I’m using version 1.0.200 from the Play Store.
As the feed is effectively streamed, the blocked community should just be excluded from the query for getting the streamed feed as new cards are loaded beyond where the user has viewed.