I just tried this 4444 texture thing out with an old opengl driver from ut-files.com/index.php?dir=Video_Renders/ and used it on my steam version of UT and it took out all the shadows in scandi..the corners are 'darkish' where shadows are supposed to be, like under the sniper bunker in the flag room, but when someone stands there they stick out like a sore thumb. When I have more time I will test more maps but..really? Really?...
Granted it made everything look like i was playing with a VooDoo3 again but it was definitely playable once you got used to it.
edit - tried coret and ec2, shadowed spots look normal but player skins seem to 'pop out' a bit more in those locations