I subscribed to this community with alts on the most populous instances:
- lemmy.world
- sh.itjust.works
- lemmy.ml
- beehaw.org
- discuss.tchncs.de
- reddthat
- lemmy.blahaj.zone
- lemmy.ca
So those at least should be covered, but it’s always good to see if people from different instances are correctly federated too
sdf.org working great.