To be clear - I still don't think he's a nonce
There's no evidence he's a practicing nonce, but he's so very nonce-adjacent, in his friendships, in his taste in anime and movies, in his attitudes and values, etc. that he appears indistinguishable from those 'minor attracted people' who just haven't acted on their fetish yet.
As far as I'm concerned, those people are still nonces. They just haven't been convicted yet. Is there a small number who never act on their desires? Perhaps. They're always looking for quasi-legal ways to get their needs met without running the risk of ending up in jail. But they still belong in the greater nonce universe.
It will be quite funny if he does end up being on meth. I'd be surprised if he sunk that low, but he always finds new and exciting ways to be disgusting.
I think there's a very strong likelihood of this happening. Nick isn't like your usual early 40's recreational drug user -- discovered drugs in their late teens, went through a period of intense experimentation, found the chemicals that suit them and settle down to stable recreational use -- doing a gram of cocaine at a dinner party between four, once a week, for example.
Rekieta is still in that honeymoon period. He's still experimenting, it's all good and at the moment -- judging by his appearance on the beakstream -- he's got the opinion that if some drugs are good, then more drugs are better and most drugs are best.
Given that, I'd expect him to be completely open to the idea of trying meth -- and particularly, as you point out, because it has a reputation for enhancing sexual degeneracy. If he hasn't done it yet, it's just a matter of time.