I appreciate your anxiety is in part coming from you feeling you're different from the norm bestman wise but I've done a few and you wouldn't believe how many people in the crowd will have your back.
I would hope even transphobs put aside their silly prejudices and recognise that supporting you, the groom and wife.
Believe in yourself and smash it out of the park
Literally just had to explain to my wife that her friends may be OK visiting as they are white but that it's not a great idea to be travelling to the US.
Regrettably I feel it's the minority in alot of countries that have these moral sensibilities