You are correct that Stans' should not be used with CO2 as the permanent gas in your tyresErr....I thought co2 was a no no with Stans....causes crystals to grow or something.
Its funny..I'm in the same boat as op. I've googled this stuff, and wierdly..you can't find an article that does a good job of explaining everything in detail.
Maybe there is a thread here on mtbr..but its not obvious, at least to me. You can search here and you will get a ton of threads, but if there is a difinative thread its buried by the sheer number of threads that come up.
End rant...but really.. I could have sworn that I read co2 shouldn't be used with Stans.