i've always given the advice "program in english, comments, variables, function names, everything", and "always use a uk/us keyboard unless you absolutely have to enter localised strings, and even better get someone else to do that"

No. You want 'for' to be a looping construct with no other meanings.

Seeing code in my native language makes me laugh, I can't take it seriously.

As someone who's spoken English since 5, I'm perplexed by this question. I'm genuinely unfamiliar with any perceived downsides and I would love to hear more of your thoughts