I voted option #2...
Im not interesed in PK, but i still apreciate any improvements in it. But i also think this change will make mnt breakable in PVE, which is a really expensive item as is it. If they become breakable, i think prices will go even more high also :-/
Option #4 is also acceptable imo, that way u can improve pk without getting involve with PVE.
Excuse me for my english