FlightPathOBN:
The 'sample' plate they give, shows quite a few waivers, first off, the different RNP levels, RNP 0.15 at the IAF?!?!?, the angle before final segment (they dont want to admit the FMS would do some sortof turn here), missed approach less than RNP 1, DA of 276, but you must make 4000' by WODVU ??...I know this is an example...but I believe this is the plate for KPDX.
None of the options shown all those example charts require waivers. They are all provided for in criteria.
What is supposed to require a waiver, but this comes and goes, is when a single-string line of minimums cannot be provided as one of the lines of minimums. This often requires two procedures to a given runway.
Climb gradients are very common in RNP AR IAPs in the western U.S. Some are at the maximum of 425 feet per mile, others are close to that.
I can't speak to a 'Copter RNP AR. Those have been designed by one third-party developer who has the expertise.