I'd ask yourself have you actually found a limits of your current setup that you can for sure say an inch or so of wheel travel will give you that much difference? Looking at your setup I doubt. IRS travel won't be great regardless yet it's pretty good as it is. You won't make it into supreme rock crawler. Front suspension is far more limiting any way. If you are searching for traction get a locker or better two. You've got nice blog. Traveling alone into remote places I'd invest into winch/bumper/pull pal first. That actually will improve crawling ability a bit by shifting weight up front.
Yes, that's really the question here, what are the limits...
I've been working on a baseline here with the luxury of having an outstanding 4X environment five minutes away. I spent hours out there this week, practicing in crossed, deep ruts, sand, steep descents, off camber descents, ledges and drop offs.
While I've been off road with this casually, I havent really explored the limits. Better feel for approach, departure and break-over angles, the surprising amount of stock suspension travel. And, of course, it's a blast.
It's not my intent to rock crawl with this, but to have the overland capacity to explore The Grand Staircase where I live. This Monty also pulls duty towing a horse trailer, so it would be unwise to pull the ASB.
Recovery is the priority, then suspension.
Thanks, all, for your insight.
And if you're ever in this neck of the woods, I'll be glad to introduce you to Warner valley.