Yes, I knew that but thanks for pointing it out, anyway. The "von Neumann" method only breaks if you had a coin that produces 100% a particular side. But then it's also apparent that by rule 2 you'd have to always discard the toss results and can't progress at all.

I just wouldn't feel comfortable to use a heavily biased coin for such tosses and therefore wrote that "slightly biased" is still fine with this method, even when "heavily biased" would've worked fine, too.

Probability stuff is somewhat non-intuitive, at least for my wet brain v1.0beta.