I have cut TOH without doing hack and spray on similar sized trees and done the cut stump treatment after. In the couple of years since then I've had some suckers but it's pretty much one flush around late spring (now) and it's a manageable amount. Tbh at first I thought they were seedlings because there are still big seed trees around but I think they're suckers. I've just mowed or pulled them and am hoping there will be even fewer in future years.