Hey Edyth~ I know you from Quetz. ^^ Yes, that would seem like a pain for the summoners who already completed them and I know one of my friends from a long time ago completed them when summoner was his first main. This was back in the day when the game world felt so real to us that I would pretend to be the guardian for his female character's summoner.

I am fortunate that I didn't lvl SMN until a few years later so I already obtained all the avatars through prime fights and I still have these quests remaining which I purposely saved for last. Now that I have Waking of the Beast completed (which those quests came in handy to warp to the avatar crystals fast) I think I got everything I needed out of the prime fights and any other fights based in those cloisters that I will soon face the solo SMN fights to complete the quests since I'm a quest junky.

I still hope SE will fix this though in case I ever need to go to those cloisters in the future for anything and also to help out other players that need them.