So people who go through a female puberty have their breasts naturally stop at a certain point. And that can change with big hormonal changes like pregnancy but otherwise you have a 'default' size in a sense.

Do y'all think that AMABs on PM after going through male puberty also have a natural stopping point? Or will there be continued growth as long as you keep taking PM?

From what I can see and read, growth while taking PM doesn't stop. But it's slow enough that at some point it may seem to have disappeared. There are men in their 70s on this forum with DD boobs grown on PM that keep on taking it and growing. You are unlikely to hit a triple D on PM alone in just a few years, but I don't think that it stops. Also, PM seems to work even on genetic women who have stalled with growth years ago.

Very interesting Shirazmn thank you!

If in the first year you grow 2 cup sizes, the 2nd you grow 1 cup size, the 3rd you grow 1/2 cup size, the 4th growing 1/4, 5th growing 1/8th, and so on until you keel over, you technically will have a bigger size each year, but you won't ever exceed a D cup. so is that non-stop growth or a default size?