In the absence of a native one for elementary OS, i’ve found a cheeky little screen recording app called Kooha on Flathub. It has options for choosing which display/window to record plus audio ones for mic and desktop sounds and it also saves to mp4. I’ve been daily driving elementary again for past couple of months and it’s firmly cemented itself as my go to desktop environment again. I’ll post in more detail about my experience later on.