Although it has belt tensioning adjusters, I think people presume you have to push the boom in as far as it goes (as per torque tube) and adjust. Need to remember to treat it as a normal tail belt drive and loosen the adjusters off, pull the tail back to get tension, then use adjusters after. I did it myself with the 470lp I had last year and could not get decent tension even with the adjusters fully in. Not made the same mistake with my latest one though but as per all manuals, they presume you already know.
Regards
Chris
(The Flying Hippo)