Is it obligatory to make up the prayers that were performed after an incomplete ablution due to ignorance of the ruling, or is there no making up for the ignorant?

The obligation of tripling the number of wipes (in istijmar) is a matter of dispute. If you act according to an opinion held by some scholars, there is no blame on you, and you do not need to repeat your prayers. We issue fatwas (religious edicts) that tripling is obligatory, but issuing a fatwa based on the weaker opinion after an action has occurred and rectifying it would be difficult is permissible according to many scholars.