From Fellow Opus to manual grinder: which one?

Hi

I have a Flair Pro 2 and I use the Fellow Opus as grinder but I find that is too difficult to dial in the correct grind size, is a bit unconsistent and sometimes one step of the inner ring is too coarse and one less is too fine.

So I want to buy a good hand grinder to maximise my result for the money I spend. I prefer medium dark roast but I’m searching for something that works great in all situations. Like a sort of “endgame” manual grinder.

Any raccomandation? I saw J Ultra and the Kinu m47 but I’m open to other options too. Thanks a lot in advance