My theory is if you suppress T in a male using E or CPA, then get off, the T will shoot back with a vengeance. It's the opposite of a body builder taking T, it makes the endocrine system lazy and shuts down normal T production. Then it maybe never come back, which means TRT for the rest of your life.
Another note, in my 4 month cycle I taper down the AA's in the last month bringing the T back and my hair quality feels and looks good. My theory is T is good for a short time but not a long time. And think the surge back in T brings with it growth hormone which plays a part in boosting hair. I would post a pic of one FtM transition, but can't post a photo for some reason.
Also consider how a teenagers hair gets thicker and fuller going through puberty, when the male hormones kick in.