I don't really see a need to share that to non-boys; it seems to usually be boysclubs. Never seen that happen with non-boys, at least.
> I think probably I need to be technical co-founder, or a trusted first/veryearly hire.
No, that's not about that. I have been that multiple times, still ended up with a boysclub. You have to be a "cool kid". Like in schools, there is no one rule for that. Sometimes you'll have to be good at sport, sometimes look badass, ...
And then again, if you end up being the leader of the group... maybe you are the one doing to the others what you were trying to avoid. In my experience, those people always genuinely believe they are loved and admired, even if the first thing employees do when they have beers "privately" is complain about how much they hate those leaders.
I guess that's the problem in being in the dominant position: you are biased, because you are in the dominant position.