Personally or one option at least:-
I would ask your friend for theirs when it expires,
TagInfo dump it, record antenna capacitance
Throw it in a glass of acetone and see what the insides look like ( Or shine a bright light from behind )
Share you discoveries here
Basically he (satur9) is / has been testing the viability of conversions with The Visble chip on a Chip and Pin card
This has been mentioned in the DT Club.