Depends on how you’re doing it. It’s common to be subscribed to multiple versions of any particular community and those cross posts will show up alongside each other in the feed.
This might be an unpopular opinion, but that sounds exactly like spam to me.
I get the cross posting, rationale but I hate it (maybe I should just unsubscribe from the dupes?)
What they need is an optional way for the client/server to collapse/merge similar links into one “post”.