Well I'm playing around with the compiler source and so far I have a version which compiles maps up to +-8192 units, which can and will be increased to +-16384 without too much trouble. The entire map is rendered in game, but collision detection apparently has a fit when dealing with anything past +-4096 units. I'm now trying to fix that.
EDIT: After this works, big maps will soon start hitting other limits, so I might try and add support for a seperate expanded limits BSP format