Many yes. Some people will find it stops being possible after many years on HRT, often from not using it (it’s kind of like a muscle, it can atrophy from non-use). It can also depend on remaining testosterone levels for some. There can be a big difference in functionality between none and an average woman’s T levels.

Like the above commenter said, yes but situational. The one thing I would add is either the blocking of testosterone or the estrogen(I dont honestly know) causes a change in the elasticity of the skin of the penis, making it smaller(shorter mostly) over time. The spongy tissue that makes the erection doesn’t go away, so there is a particular shape for feminized erections that is particularly noticeable. The girls you see in porn are likely not taking hormones or have some sort of T cream they use to keep a huge cock. I’m poly and t4t and I’ve seen a fair few girlcocks, I don’t know anyone personally who doesn’t have that distinctive shape regardless of how big they are if they’re on hormones.