>>30157I have a very specific scheme in mind, which i'd hoped would be aided by something like inheritable x properties, but since they don't exist a kludge it is:
/etc/profile runs a script writing the window id to /run/foo/$$. If a new window is spawned, get the process id with _NET_WM_PID (fails with 9term, so much for icccm compliance), then walk up the process tree using ps until encountering a process in /run/foo containing the window id with which to set the correct geometry.