Hi there, I came close to ragequitting, but I finally beat the Curator during my 2nd visit to the Shinra building. However, he didn't drop anything after the fight ended (which, according to a video I checked later, isn't normal), and he respawned right after I left the room. I don't think there is anything worthwhile when you get to beat him (unless that Micro Engine does something later), so I was thinking of just ignoring the Museum room and continue with the story, but I'd rather have confirmation I'm not missing out on anything.
I'm playing the Steam version, and I only applied the latest New Threat mod (and fixes that came after that), so I really don't know why it keeps coming back, considering it died for good in the video I checked afterwards.
I also came across a problem during the fight. Tifa got her Grit triggered while she was grabbed by the Right Arm, but the arm didn't let her go when she died again, and kept her until it died, still damaging her and charging her Limit Break, even though she was KOed. It happened to me a few times in my previous fights.