OK, time for an update.
I got my local tire place to retrieve the fumbled tire stems and insure the new ones were properly installed. Inflation of industrial skid steer tires is to 60 PSI, max is 65 PSI. So, rims now fully capable of being mounted either way without interference with axle housing or king pin.
I called my other Kubota dealer, they've been in tractor sales/repair business since before there was 4 wheel drive, and posed my question of reversing the tires/rims for additional width. He understood the question. They've been Kubota dealers for excess of 15 years now. He didn't see that there would be a problem, although I did get a lecture regarding being careful on slopes. I pressed him, to the point of embarrassment, about problems that might arise from doing this. Would it tear up the bearings or seals? He didn't see that there would be any problem. Had they seen problems with seals/bearings on 4wd tractors over the years that could be explained by reversed rims? No, not that he could recall.
So, I mounted mine reversed and went out with the scraper to see if I could perceive any additional stability. Spent about 2 hours in same location as prior scraping.
My impressions are subjective, no scientific technique seem to be available other than simply the number of times I concentrated and felt concerned regarding tippiness when turning down hill. I have to say that I think it was slightly improved. There were a few times when I thought that the inside wheel would dip further down and things would be more unstable than they actually turned out to be. ...So overall, a possible improvement from a stability standpoint...clearly, did not get worse. An unanticipated result is that the front tires are now easier to see and judge where they will go, both right and left, since they are a couple of inched wider stance now on each side.
So, current score is....
2 dealers do not see a problem doing it
several manuals say don't for other models, but don't give a reason why
Numerous TBN members are dead set against it with dire warnings about the outcome.
All agree that side slope stability is something to be very careful about.
There is animated discussion about whether the extra width will or will not result in better stability, however slightly.
Me? I'm still kinda on the fence....thinking that I might leave them reversed for current task which encounters uneven conditions and slopes, then put them back when this task is over....so, stay tuned....