You can debuff yourself and gain stats all the way to 120. You can even fight mobs that debuff you (Oathlieges and some champ mobs come to mind) and gain stats as you farm, but you'll farm slower. There's also no reason to think useless mob spawns would become valuable all of a sudden by changing that. Could you elaborate? Few hours? 1 forest golem is worth 30-40k and takes a few minutes to kill. There are some good mobs to farm out there right now.