Back to KTM : the RNAV APP there is a basic GPS one , not with vertical guidance and it is a 2D
I doubt it, if you're referring to the approach in Aterpster's post 22.
Our CAA rules for conduct of an RNP-AR approach: "After the aircraft has passed the FAP or VIP on an approach, deviation from the defined vertical path must not exceed the limiting value for vertical deviation stated in the operator’s RNP AR operating procedures." = 3D approach.
Note that the minima is a DA; no point in trying to fly to a DA, especially with a vis limit of 900m, if you're flying some sort of pilot-created profile.