JAROps, seems to me, almost removes the DA/MDA distinction.
And takes them further away from ICAO. Makes me wonder why anyone bothers to refer to ICAO at all. About the only time that Pans Ops allows "sink thru" in a NPA is with a VNAV approach.
Did you find those height margins in ICAO doc 8168 vol 2?
I think that you'll also find the height loss margins in Volume 1.