ENHF has one parking spot, stand 3 (would love to use Stand 2 though). It's too small for the Dash 8 Q400.
It's not clear which scenery you are referring to. The default scenery for ENHF has 4 parking spots + 1 Fuel, and one ( Parking 1 ) has a 14 meters radius, so it's large enough for the 27.0 Wingspan of a Dash 8 ( 14 * 2 = 28.0 max Wingspan ).
A single parking 4 meter radius seems to be a bug in the scenery but, the real issue is there's no *other* parking to spawn vehicles from so, to be usable in GSX, a scenery should have at least 2 parking spots, one for your airplane, and at least one for any vehicle not starting in your own spot, like the Passenger Bus, the Catering or the Fuel vehicle.