Disagree, third favorite episode behind Reaching Out and Thanks to them. It had a solid conclusion to the characters arcs, it sold me on the collector as a character after being skeptical about him for 3 episodes, and strong emotional payoffs
You already said you disagree, but... I thought Once Upon a Swap was actually a pretty fun episode. Yes it's "filler-y," but I don't mind the "filler," and I thought that one was funny.