Respectfully Monte I have to disagree with your assertion that the P5 is tippy, (compared to what)? Now that I've driven mine 3200 Kms in a variety of terrain from desert to swamp and snow here in Western Canada this is what I've come up with. What I can say is it may "feel tippy" I've actually stopped when it feels nasty and tried to pull it over.... Nope, now it might slide a little down slope but it so far has not flopped over. I would say 5-2 rims and I'm running 26 by 11 by 12 tires on all corners might help a little, but you are higher too. When I'm next out I'll use my iPhone level and slope clinometer to see how steep side slope I can go with out flopping it over.
As noted in other post on here, I find as I can't see the wheels on the P5 it feels awful at times, compare to my Honda Rubi ATV. Compare to ATV you can't really apply any body English in a meaningful way and not seeing if the wheels are touching (or lifting off) makes it feel tippy. Have even opened the door on the high side and hung out for a little counter balance, (really not sure this does anything, but makes me feel better). Had my son stand with door open on high side and lean out to counter. We stopped at that point to see if we could pull it over... Nope, it did slide downslope a little, only because we where pulling on the ROPS though I think.
Again next time out I'll take some measurements best I can and a pix or two.
jrc