Back to finishing off the Ryloth arc:
S01E20 Innocents of Ryloth - Excludable
The problem with this episode is that it adds nothing at all. Obi-wan goes and rescues some innocents from droids, whilst two clones we never see again meet a twi’lek child.
Waxer and Boil show up again in the Umbara arc for a minor but dramatic scene. The child is Numa (I think) and one of the two gets a graphic of her on his helmet. Numa shows up again in Rebels as part of Chem’s unit wearing parts of clone armour in the same colours as Waxer and Boil’s unit (212th? I think they’re part of Cody’s mob).
Not massive issues if you were to cut the episode but due to the same creative team, there’s basically only one episode that doesn’t connect to any other and receives no call backs in Rebels or The Mandalorian, and that’s ‘Lightsabre Lost’. Everything else is called back in some way, small or large, in the future.