When your friend dreams of having their own wolf haven, you want to help make their dreams come true; that's why I'm suggesting what has probably been suggested before, and there's probably a reason why this hasn't happened yet but I still think these two suggestions should be implemented at some point in the future ^-^ Suggestion 1: Make it possible to use a silk touch pickaxe to obtain a spawner. Suggestion 2: Make it possible to change spawners with spawn eggs, as at the moment the eggs are kind of useless. (to be honest I think suggestion one would make skygrid a bit too op but these suggestions haven't just come from me so :P)
OK 2 things, it would mean skeleton spawners in the nether which would consequently mean more wither heads and therefore easy greifing even to protected islands