I am a cis man who could not grow a full beard until I was past 30 years old. As you say, just a matter of genetics.

I remember mentioning that to a young trans guy friend of mine a few months ago when he was just getting started on T.

He was surprised, thinking pretty much all cis men have full beards or at least can grow full beards.

Not so!

I think he felt better about his slow-ish transition knowing that.