The #1 most successful way of checking a vtuber to see if you'll regret wasting your time later is to see how she treated her biggest schizos during whatever her fanbases biggest multi-person schizo meltdown was.
Any vtuber who responded to that with: a genuine sounding apology, a genuine attempt to talk about it and find a way to relate to it, and didn't hold it against anybody except herself, will be of certifiable quality
I'm not saying it's the right or wrong way to deal with those sorts of things
It's simply a lazy man's way of finding a solid choice with much less effort