Since Artemis IV clearly still works in aerospace combat, page 238 can't be all-encompassing. Likewise, standard LRMs and SRMs for MMLs can't very well be "special ammunition" by definition.
Whether ER and HE ammo for ATMs even count as "special" is unclear. The ATM writeup casually refers to them as such...but then they don't show up on the list of "special munitions" running from page 140 to 142.
If you look at the TW table there are some special rules for ATMs, and it says that if each ATM has at least one ton of each ammunition type per launcher they deal 50% normal damage at Extreme range and 50% additional damage at Short. Perhaps certain fighters do not allocate the minimum one ton of ammo type per launcher?
And if you look closely, you'll find that that text refers specifically to ATM weapon
bays. There's a bit just preceding it that deals specifically with
non-bay ATMs in aerospace combat, and that one does in fact suggest that switching (and adjusting range and damage accordingly) is possible.