There's no restrictions on the SGX drivers (not even 'don't use outside nokia devices' or 'no commercial usage'), but you would have to use Debian armhf to use them as they're in hardfp ABI. If I was you I would use the new drivers, the kernel drivers are open and we support vsync. Userland is naturally closed, but redistributable.
There is very good reasons why Maemo is like it is and not just a UI slapped on top of upstream Debian. It bends down to how the software performs in a mobile setting: the memory footprint, the wakeups software does, the storage footprint. Maemo and MeeGo did a lot of slicing and dicing that was needed to provide the quality mobile products you see now.
Anyway.. starting sometime after March, I'm returning to being just a community member around here, with no special accesses or privileges