I suspect both could be correct, for both issues.
I know for certain Milans were scarce, for even the Panzergrenadier IFVs, so each platoon only got one initially, and later, two. Presumably, eventually every vehicle/squad got them.
My guess is the same could apply to the PzFst 44s also.
I'd certainly think one per squad to be the most likely, given the superiority of numbers of Soviet and WARPAC armor the West Germans/NATO were up against.
Can't say definitively though.
Also, around 1989, units would have been at the height of their strength as well, just before the wall fell, and the Cold War ended.