No danger of it reverting, I've seen them used here in the SF Bay Area, similar in all respects to the other cultivars. This one will still have some of the other problems with the species; they are surface rooting and difficult to garden under, and tend to suck up a lot of water away from other plants, plus they ultimately get very tall. If you have the room for one, and are not trying to grow less tough plants underneath them, go for it. The fall color on these is worth the price of admission!

Does anyone have any advice on how to propagate a seedless sweet gum from an existing tree?

Thanks in advance!

Summer softwood cuttings with IBA, mist and luck.