It only takes a few seconds for a new map to load though. By the time a load screen would load, the map would already be loaded And I'd rather not have it set to a timer and be stuck looking at a static screen for 10s if I know the map is already loaded, that would be a pain for matches when a team keeps switching maps (although it would be good for newbie pubs, so the cvar xbain suggested would be required if this was done)
How about an "OK" or "Play" button that appears when the map is done loading that closes the loading screen?