How many feeds is he actually having a day now?
Sometimes a quick feed doesn't mean he hasn't gotten a lot, they get more efficient as they get older so maybe he's just a good sucker
Personally if he's sleeping well, having plenty of wet nappies etc and he's gaining weight then i'd continue with what your doing, maybe no offer any 'extra' solids if he doesn't feed but i wouldn't be reducing any if he seems to like it now.