I do not use video chats but for me taking pictures within the official signal app works - both for posting them in chats as well as for registration of secondary devices.
@khoffmann69 it should indeed work, we have setup camera in a way that doesn't block the usage from android. Our native camera app also frees up the camera object and allows usage by other apps when running but not focused. These changes landed this month so you should definitely update first
Yes. The camera works. I had initial issues only with QR code recognition. I tried to access for eSim and couldn't do this. A blue box shows and it should work for acquisition, but one has to press within that blue box and that is not well documented. I did in fact try that. It subsequently worked with a QR code sent by Furi Labs to check it out. I am unsure if this was only a one time glitch or no.
BTW Screenshot gotten by sustained press of log off as option there. Possibly a Waydroid peculiarity, but new to me.