I honestly think that HRT is really necessary in just 3 cases. Either you must be trans, having serious medical conditions caused by testosterone, or suffering from "testosterone poisoning" in its traditional meaning.
"Testosterone poisoning is a popular term used to explain behaviors that are deemed excessively masculine."
So basically, if testosterone induces uncontrollable behavior, where you can't be calm and think clearly when needed.
In my case, I need to be calm all the time to think clearly, because (by nature) when I'm not thinking clearly, I get instadepressed. TBH, I started HRT out of curiosity to see what effects it'll cause and was pretty sure to quit at some point, but stayed ultimately for this one effect (which btw I realised only recently). Other "meds for calmness" weren't even close in terms of quality and naturalness. Its like long lost childlike spontaneity suddenly reawakened with all its perks, like constant contemplation and seeing things as they are intended by nature, but with the additional adult ability of seeing the big picture. Honestly, looking back on my post-pubescent years, they now resemble the goofy attempt of an uncanny anthropomorphic creature to imitate how humans think and feel, while its constantly being FKed by firware, forcing it to be edgy..
Sry, got a little carried away. So basically, what I was trying to say... If feminine gay guy is comfortable in his role (not trans), doesn't have serious testosterone induced illnesses and can think straight (not mind-poisoned by T), honestly, no HRT is needed IMO. Again, HRT just for hair to me smells a bit of rather delulu, or there is another hidden reason. And that reason might be hidden from the owner himself, like it was in my case.