Is it true that 30-somethings with acromegaly won't grow any taller @ this age? is that true even for those with just mild symptoms of the disease?

It Depends: If you got acromegaly as an adult after growth stopped this is true. However, if not treated there can be serious side effects (hearing loss, chronic headaches, arthritis, type 2 DM & others). If it was acquired as a child & not treated this is correctly termed Pituitary Gigantism & can have same symptoms. In this case the growth plates may remain open & cont growth theoretic poss, but very rare!