Mhh... you could try ticking off the CSG, BSP and VIS lines, perhaps the compilers will used the files generated during the last compile. I doubt if it'll work, though.
What I do know is that you can use cordon compiling, e.g. you use the cordon tool to select a part of the map, and compile that part only. This is especially handy fur test purposes or for fixing lights or entities in a part of a large map.