I hope my feedback on your earlier post didn't come off as mean or anything. I know I gave you a bit of a hard time since we're not exactly aligned on how to solve some of these problems, but I do appreciate your attempts and the work you are doing.
I don't know how hard it would be, but could Fediseer be something admins can send messages to directly within Lemmy? Could it make sense to just have this work over PMs as a primary interface? This would let onboarding for unclaimed guaranteed instances be as simple as admins responding to the PM they got.
Alternatively I think there is probably a lot that could be done in some sort of web interface whenever Lemmy decides to be an OIDC provider so you admins could log in to Fediseer via their instance. But that is probably a long way out, there is so much to be done within Lemmy.