I have a 900 with worksite tires. When I first got the buggy I ran the recommended 20 psi. Not anymore.
I have 16 in them currently. Where I really noticed the advantage of dropping the pressure is when plowing snow. I started running 14 psi in the winter and it was night and day difference. Traction improved to the point of doing most of my plowing in 2wd with about 300 lbs. ballast. I wouldn't be surprised if I could go down to 10 or 12 psi.
I have seen no ill effects with dropping pressure. If you ran full speed with a full load on hard surfaces you may build some heat. I have carried some big loads of rocks for a few miles and not noticed any problems or increased heat.
We all know that these rigs are not high speed monsters so I don't see any problems dropping down, as long as you do it within reason and monitor them.
May also depend on where you are located and temps there.
Hope this helps, and interested to hear other comments.