You would think they would know I bought the tool. While putting in ads like this may be mainstream for Windows folks, I find this highly annoying on the Mac and quite frankly I think this behaviour needs to be avoided at all costs and I'm not sure this complies with some of Apple's guidelines. I'm surprised Corel has done this (well maybe not), but I'm surprised that it keeps appearing.
For those on Mac Big Sur:
sudo spctl --add --label "DeniedApps" /Library/Preferences/com.corel.CUH/CUH.app/Contents/MacOS/CUH
sudo spctl --disable --label "DeniedApps"