Andy,
A 1500# tractor is a big difference from a 3000#+ tractor. Add loader, operator and what ever might be on it, then it can be closer to 4,000#. The website that I referenced just happened to be the first one that I looked. With this website I would not have a concern either. I had, in the past, found a couple of websites that talk about weight in the 2000# area. I was the same as you, an occasional vehicle, 2000# tractor so what. It was not what I read here on TBN, but what I have read on septic systems. Some of sites dealing with septic system recommend only push mowing the area. Will I, No. Will I use my CK20? Unlikely, but time will tell.
Last year I used the CK20 to mow my front yard at my house, which I normally ran the long direction, then when I switch direction and I was surprised the number of bumps that were caused by tire compaction. Just an observation for this yard.
Kurt