Another problem, their site refers to the 549 Exemption letter as the master source document of airworthiness. That exemption letter was cancelled 6 YEARS AGO.
It was? When I imported my RV-6, five years ago, the exemption letter was in force. It allowed me to use lettering less than 3/8" high on my passenger warning placard.
I had brunch with one of the local MD-RA inspectors yesterday. I mentioned this situation of not being able to get your system checked without flying to an airport with an avionics shop. He said that for airspeed calibration, he accepts personally calibrated airspeed gauges (ie. with a manometer) if you can show the science behind how you did it. If you just say "oh, yeah, I calibrated that" you won't get a pass. If you show photos of your manometer setup, a log with the data captured, you could be okay.
He gave one of the aircraft a pass with the condition that in the first 25 hours the altimeter/transponder system be checked at an approved place. The restriction did specify that he couldn't fly into transponder airspace to accomplish this... So he had to find an airport nearby that was outside transponder airspace but with a shop capable of doing the work. That was possible in this case, with a short flight.
It sounds like they are allowed (or are just doing it anyway because it's the only thing that's reasonable) to make judgement calls when appropriate... But the regs and MD-RA policy are there for them to fall back on when an owner becomes unreasonable... which does happen.
One builder told him that everything was calibrated and it was ready to go, but when he stuck his head under the panel the pitot line wasn't plugged into the back of the airspeed indicator. Needless to say, that builder didn't have any calibration data to show, nor was there any sign of any equipment needed to make a manometer, etc... He didn't get his paperwork, and had to pay for a second inspection.
One import inspection didn't go well because when he arrived the airplane was all buttoned up with inspection covers, cowling, etc. in place. The owner didn't want to tear it all open again because he had "just closed it up after having his mechanic inspect it." This despite the inspection paperwork clearly stating that the aircraft must be completely opened for inspection.
I think most of the problems people have with the MD-RA are brought on by the builder/importer just not reading and understanding the requirements. If you're in the middle of nowhere and don't need a transponder for your first flight or first 25 hours of flights, don't install one! There's nothing wrong with having an empty space in your panel. Once you're signed off, then you can call the local airport with the avionics shop, ask for one-off permission to fly in without a transponder... for the purpose of installing and calibrating one. You'll get it.