Yes, but it might screw up the balance. The current model requires us to fight as much as we can, let's say, for a month; that includes killing 3-4 bandit groups within an hour frame (of in-game time, hehe). If we change the rules like that all of a sudden, we'd have to increase both money/loot from encounters AND experience. Lots of tweaking, I'd guess.
Maybe we could try with that; a penalty for too many fights, but in return, make the battles give us more XP, gold, loot - and make them even harder.
(I always play on "Mummy" and I still find it quite easy way too often.)
If it doesn't ask for too much of your time, code it and release as beta/test version, I guess there will be some other volunteers and to give you feedback.