Of course.
It has been enabled during installation only. BTW there's HD2500 Series which AFAIK is not compatible with MacOS X.
So, if it'll be useful I can tell my installation order:
1) Removed GTX 570 from PCI-E, switched to iGPU in BIOS
2) Booted from USB flash with GraphicsEnabler=No
3) Installed OS X 10.8.4
4) Switched to PCI-E GPU in BIOS, put GPU in place
5) Booted from USB to -s mode, removed all of the Intel, AMD and NVidia graphics kexts
6) Rebooted from USB to installed on HDD MacOS X and here troubles begins: I've got "NTFS Volume name bla-bla-bla".
I've tried GE=No/Yes, PCIRootUID=0/1, -v, -f in different combinations (bruteforce, yeah).
Any ideas?