No... the HID system does not have the manually switched level control, it is entirely automatic.
it basically consists of 2 sensors, one on the front left, one on the left of the rear suspension sub frame, attached to suspension components, and a control unit in the front right wheel-arch/suspension turret ..... the control unit computes the car's angle/attitude and then controls the Lamp position motors directly to adjust the beams more or less constantly to keep them within the required positional range to prevent blinding oncoming traffic.
in the event of a sensor failure or other fault, it automatically points them as far down as possible , and brings up an error message in the MID, which protects other drives form being dazzled, but giving you an effective night vision range of about 10 feet....

In all honesty , as far as i can tell, retro fitting HID properly is expensive and time consuming.... and , legalities aside... if you get it wrong... MOT failure is certain..... you even get warnings if the lights are ageing and showing blue around the edges..... if they're the slightest bit out of position it's an instant fail...
My MOT's due on march 9th.... so I need to sort my sensors out ASAP really...
if i had a Meega without HID, i'd choose to use the +50 bulbs in the projector headlight units as my solution..... it's easy and cheap.
and tolerably effective.