could try putting the frame in a basin of hot water. see if that loosens the hold the cups have.

Ive got a 3 peice crank on my folder bike. It originally had a 1 peice crank. Ive got an axle that has square tapers and the threads for 1 peice bb cones.
I do have a DMR adaptor cups too. So might fit them to it. I think they are simmilar to what youve got