I don't know if the Ti4600 supplies more voltage than the Ti4200 but I do know that almost all known Ti4200's were made on cheaper PCB's with fewer layers and (fewer caps I think), with the exception of certain overclocking Ti4200's, like ABIT's OTES.
I think a Ti4600 BIOS might screw up your card, and it really isn't worth it for the possibility of a minor o/c boost (most Ti4200's do Ti4400+ speeds anyway).
On a side note, the name Albatron always struck me as weird. Sounds a lot like Galvatron from Transformers to me... Plus Albatross. Albatross + Galvatron = Albatron.