They usually appreciate suggestions, so I’m sure they’ll pass this one along, but I hope they don’t take it since I personally prefer not having the warning in my way while I’m working in the UI and before I hit the print button is sufficient for the purpose in my view. It’s a reminder that there are risks to cutting things that aren’t laser safe and those risks are yours
Yes, if you put a piece of PVC in there and put a lot of work into your design in the UI, you’ll lose a bunch of work when you finally read the warning when you hit print, but hey, hopefully that’s the minority case (but also important to make an attempt to warn).