bond level 99, all party members level 99, all requests. idk if anyone will actually do it but it would be pretty interesting as a category

you could also just run plat trophy at that point. Someone did do one run of it once but didnt highlight it unfortunately. For the things you mentioned you would do a ng run + do the rest in merciless playthrough. You could route it of course yourself and do runs of it. But I dont think it would be quite interesting. Velo did route all requests ng+ iirc but never bothered doing a run of it. He also did runs of all rematches in merciless. Not added in the board but didnt stop him from doing those runs. So if you are interested in your own idea then nothing is stopping you from routing and doing the run yourself.