In there any way to bring Cass back to full functionality after completing this quest? It should be theoretically possible to do this though the console, but so far nothing I've tried has had the right effect. Maybe the fact that Birds of a Feather was completed over 40 play-hours ago on the character in question has something to do with it.

First thing I tried was the simple "resurrect NPC" sequence:

prid 00135f19 (Cass)
resurrect
disble enable

This brought her back but she would only say a line or two after which I'd only have the option to end the conversation. She was also not behaving like a companion (no wheel, wouldn't follow, etc.) Later I found:

SetPlayerTeammate 1

which brought up the wheel, but Cass still wouldn't take orders such as follow. I also tried resetting both her quest and birds of a feather but that didn't do a thing. Any ideas? Is there a way to spawn a brand new copy of NPCs? Thanks ahead for the brainstorming help

prid 00135f19
kill
resurrect
disable
enable
moveto player

No idea how to fix her dialogue problems though.

Yeah, I've tried that exact sequence and variations thereof (including variations with resetquest). It seems to be a much deeper issue that borked dialogue or disabled companion commands. Is there a way to find what EXACTLY is changed for Cass by the Birds of a Feather scene? That way, everything done there might be undone, maybe even in the right order.