The FAA the RNP AR procedures designers routinely use climb gradient missed approach procedure, and more than a few to the max of 425 feet per mile. No approval is required because it is permitted by Chapter 4 of 8260.52.
Yes you can, with 'specials', but I have not seen this with public RNP, at least with 3rd party developers, I have noted specific CG on a few plates, but very few. Without waivers, a design based solely on the published criteria would useless...18 degree max bank angle with winds being my favorite.
by 'exemptions' I did mean wavers...sorry 'bout that.
TERPs does not, and cannot, account for OEI surfaces.
Exactly my point throughout this entire thread.
Operator Training Concerning One Engine Inoperative Contingency Planning For IFR Departure Procedures.
FAA has zero enforcement options
Actually, the FAA does have some teeth in these regards..at Palm Springs, several wind turbines were relocated, but yes, you are correct, there is little pro-active enforcement, and with RNP, you are typically outside of the P77 surfaces, so you are on your own.