I read the letter that was sent to the BATFE and I did not see where it said SU motors, I read sport rocket motors regardless of propellent mass. Now I am at work so I don't have gthe letter in front of me, but I think? it also said something about the PADs did not fall in the 62.5gr ruleing.
I know a motor dealer that said bring in your case and leave with a PAD.
From what I've read on ARSA's website , single use (or fully assembled) motors are considered PAD's. Reloads are not PAD's. Where this is handy is for those making their own motors. You don't need a LEUP to create your own APCP, you need it to transport the APCP off of your property. So, with the PAD exemption, EX flyers can simply make their own grains, assemble the motor at home, then legally transport the PAD to the launch with no LEUP. Commercial reloads are still regulated at the 62.5 gram limit. Oh well - I didn't really want to certify anyway, I guess.
ARSA has been known to iterpret the worst-case possibility as fact more than once, although in this case I'm inclined to believe their current interpretation. I have feelers out there to sources I have more faith in though, asking for educated opinions on what is reality and what is overreaction.