Levelers shouldn't really be an issue as I've never known an MOT tester...test them. The test is carried out on level ground, so as long as the beam pattern is good, there should be no problems.
As for replica xenons, they are projector lights with a HID kit fitted. The problem with them is the warm up time taken to get the light output up to full power. This is fine for dipped beam, and main beam for that matter once the lights are turned on as the beam pattern is altered by means of a shutter behind the lens. However when flashing without the headlights already on, they will not give full brightness when you need it most.