thats basically how Im implementing, raspIPC.. watcher looks for a config json with coordinates and unique camera uuids and applies it when changed, and the UI just lays it down and caches changes in a lil database until applied (just writes the json file)
the trick is using the dbus interface omxplayer offers, you can change coordinates on the fly without starting and stopping the proccess.. thats what i am messing with now, loading up all the camera streams off screen, then read config and put them in place.. any unused streams stay off screen until a feed goes down, then everything moves up in priority until it comes back.
just getting it all working stable without blowing it all up, now thats a trick.. I keep throwing my monitor into some error mode right now when I add a few more feeds, and its pissing me off.. tells me my resolution is invalid.