I no longer stp in public, so I always wait for a stall. In my experience, nobody cares. Nobody wants to know why I'm waiting, and there are often other guys waiting too. I'm not super comfortable with it, so if there are a lot of people I usually leave and come back in a few minutes. The public restrooms I use tend to be in urban areas, and there are often guys using the stalls to change clothes or do drugs or whatever, so there are times that I just give up on waiting and seek out a different place to pee. That dynamic sucks for stall availability, but I feel like it also cuts down on anybody being surprised if I decide to forgo the urinals.
Guys do talk sometimes, and the people who talk are the same people who don't tend to bat an eye at any visible differences. I don't like to talk to strange men in the bathroom but any guy talking is drawing all the attention, which is nice.
I'm still a tiny bit pensive about how obvious it is that I sit down to pee, but nobody has ever asked me about it. Most people aren't in there long enough to notice even if they were paying attention, and I think if anyone noticed and cared I would see them as the weird one.