If you use #GStreamer for cameras #PipeWire support in turn comes for free via the PW GST plugin. Additionally supporting proper #Flatpak sandboxing via the camera portal is possible with little work using #libportal or #ashp and the GstPipeWireDeviceProvider. Feel free to ping me if you need help with this - there'll also be a new example in #workbench for this soon.
fmo