Flydiver - got it. You don’t think it’s a good idea. We disagree on the merits of this project.
Swapping out a driver and led star is by no means “a LOT” of modding. It’s ho-hum for many of the folks on this forum, which is why I’m asking for their expert help. I’m interested in how it can be done, and I think there’s alot of good discussion happening around the “go for it” camp.
lol flydiver. 
I like your style.
Luumensguy: it may be possible to get higher lumens than stock but you may not get more than 1200. The driver type is specific and you might only be able to do a resistor mod to get a little higher output. I’m guessing that the stock output is 800ish lumens. I’m also guessing that the LEDs are lattisbright and not real Crees.
You may be able to use a different driver that requires a normal off/on switch and operate the flashlight by twisting/untwisting the tailcap however, that would increase wear and tare on O rings and maybe more significantly, cause pressure changes inside the light which would not help with water resistance.
I can help with that. Twist on/off is a very normal way to operate a dive light. Decent lube and that’s no problem. The minor pressure change that this creates, which is a very small increase, in no way should affect the water resistance. Compared to water pressure it’s less than trivial. If it can’t take that, it can’t even take dunking.
Good point!
Thanks again guys for your feedback.
Eebowler - I’m looking to replace the driver AND the LEDs, so no reason I can’t get the output I want.
And yes, looking to make it a twisty. I think the 1 mode driver would take care of that.