The real safety and vulnerability issues here???
The real issue here is the unnecessarily and inappropriately high DA(H). Properly designed RNP procedures with correctly applied Baro VNAV VEBs are typically good enough technically to support DA(H)s down to about 250' HAT or even somewhat below. So any unnecessarily high DA(H) situation leads to potential risk of visually mishandling the trajectory below DA(H), ...just as with the KSFO B777, KBHM A300, or recent Libreville B747-8 hard landing for that matter. So while these RNP approaches provide vastly better vertical guidance to about 200' HAT than any other VOR, VOR/DME, NDB, LOC, or BCRS approach, ....we still eventually also need the benefit of GBAS/GLS, to provide the accuracy, integrity, and availability to support use of LAND3/AIII modes all the way through flare and rollout for these kinds of marginal visibility situations. GLS/GBAS is both entirely possible and economically practical at places like VNKT, to augment and complete these already better RNP approaches than any other alternative.
Both the terms "Precision and Non-Precision" are long obsolete as a practical matter, and were even dropped from use in references like FAA AC120-28D and AC120-29A. The FAA/JAA/Industry AWO HWG even tried to once move ICAO and ANSPs toward simply designating approaches as 2D or 3D, recognizing that any and all approaches need to be flown "precisely". Further, RNP is vastly more precise than even ILS for much of the total track mile distance of the arrival procedure, until typically very close to the runway, and for ALL of the MAP. hence it is instead ILS that, for locations like VNKT, would more appropriately be considered as "Non-Precision".
WAAS and EGNOS are SBAS. WAAS IS NOT CONSIDERED to be GBAS, period, even though it uses a few ground reference stations to derive the space broadcast corrections.
Only GLS (and JPALS and Portabas and equivalent) are considered as GBAS.
None of these RNP procedures should need to be considered as AR any more by authorities globally, beyond simple applying criteria like FAR121.445 compliance. RNP and GLS, as well as use of LAND2/LAND3 are now basic elements of safe routine operation of any modern transport jet. Instead, it is ADF/NDB, VOR, LOC, BCRS, PAR, and "Circles" that perhaps now ought to be considered and treated as "AR".