Kinda news to me. Just read apparently pH can affect the duration of amphetamines, so it can help in that regard. I guess that's what you mean?

Still bit dubious, as it depends more on your overall diet rather than just a single supplement & there are other factors that will play a role too.

AFAIK, the only real benefit to taking magnesium as far as stimulants are involved, is to relieve bruxism etc.

Quite common for people who drop MDMA to take magnesium for such purposes. Not that I'd know anything about that of course...