It is pretty clear, that RNAV-Z is not a normal RNAV RNP approach designed to bring one to the runway but just to break clouds, I think that has been substantiated enough (and it is written for example here: https://www.doat.gov.bt/aipp/wp-content/uploads/2018/11/AIP-AMD-01-2018.pdf)
But that is not the essential point - the essential point is, that the FAF is at around 13.000ft, which makes it impossible to dive down for a straight in landing into rwy 15, EVEN IF one is out of the clouds there! (that would be almost 7 degrees - it’s not only not 3 degrees or 3.5, it is over 7). That is nothing an Airbus or 737 pilot would fly. The RNAV-X and RNAV-Y approaches are different - they end at around 10.000 sufficiently away from RWY 33, so those COULD be used for a direct in into 33 (though they also allow RWY 15). So in essence, the only conclusion I can take from the RNAV-Z RNP cloud break approach procedure is, that is indeed to be used to get into VMC, and then fly the usual course reversing procedure into RWY 15, if RWY 15 is the active one (i.e. north-west turn over the airport, remain > 11.000 and then turn south-east and sink into the value - just as the VOR PRO based procedure describes. A 7 degree descent is not a good solution imho, a jet plane that does not speed with that gradient has not yet been invented.