Jesus, 26 pages in 8 hours since the thread was created. People have some very strong opinions on trans men.
...honestly I don't fucking know. I don't really compare transmen to transwoman because their motivations and approaches to the transition are often very different. Trans men put a LOT of work into looking and acting stealth, so they do a far better job of acting and dressing normal for a guy - and they pass as a younger skinnier man. There are a few like that Elliot Paige that has made being trans their identity and are nasty, but it is completely different from that madness that MTF troons do. I can't imagine a FTM trans sneaking into men's changerooms to watch or grope while flicking himself - and even then there may be some guys who are into that.
I'd have to ask and actual FTM guy what he thinks of straight guys pretending to be gay to fuck them as I have no idea. There's a lot of hurdles involved that would lead me to suspect that said guy is secretly bi-curious or something, as they will be undulated with gay guy dating profiles and if remotely attractive would be regularly DM'd with offers to fuck or be fucked (sometimes with unsolicited pictures and videos).