I see a fair bit of LXQt, whether it is on my one desktop that is running it on top of a Debian install, or my preference for laptops and virtual machines which is to install Lubuntu for fast pain-free installations, especially with non-free firmware and low resource use. Debian remains my preference for my desktops due to its versatility and feature set being more oriented to hard core geeks like me. Hence the one desktop that is running Debian/LXQt rather than Lubuntu, which is annoying in having disabled hibernation, among other things.
One thing that itself is a nuisance on a computer for screen recording is the popup desktop notifications in LXQt, which for example take over the browser message popups, or the on screen feedback to up and down volume buttons being pressed on the keyboard, and as far as I can tell, always appear on screen 1. There is only one way to get rid of these, but you can’t configure them by application as you can on some desktop environments. Nor is there much control over them in the LXQt config center. So it is just easier to turn them off altogether.
Just go to LXQt configuration center, open Session Settings then on the first screen “Basic Settings” in the “LXQt Modules” window, find “Notification Daemon” and stop it, then untick its entry as well.
You will still have to look at browser notifications – I recommend turning them completely off as well.