Don't take this the wrong way, because I totally don't mean it to come across as such, but what is the fixation with raising stat caps to such high values? I've always wondered and never really had a good understanding of it.
I guess what I'm saying is that, at least in my experience, the most rewarding changes to combat have been the ones that add more realism to it, make the sequences more natural and less rigid, i.e. "I hit you, you hit me, then I hit you again" stuff. It's much more fun for everyone involved when the fights behave at least a little bit more like the real thing, or at least the "ideal".
Little things, make a huge difference. Case in point, I could never stand how being immune to certain damage types meant that your opponent wiffed it (missed) 100% of the time, whether they missed you or hit you but did no damage because of immunity. At the end of the day, it was always "So and so's <dam type you're immune to> misses you!" ... barf.
It's much cooler to pop a message saying, supposing the blow actually lands, that your opponent is somehow unfazed by your crushing blow, or whatever. Even a less than astute player quickly realizes he's not just wiffing it, but that his opponent is actually immune, and that's a meaningful change to the realism and dynamic of the fight.
Anyway, not trying to rib you, just throwing out my $.02 since you brought up combat and sounded like you were looking to make changes to it (hopefully not limited to the present issue you are facing). I find these kind of tweaks infinitely more fun than raising stats or HP to huge levels. That said, I must admit that I do have a few mobiles with massive HP, but that's for another purpose altogether.