I second that. Why descend any sooner than necessary, especially in mountainous areas of the third world?
Having said that I can only speak to the rules in the U.S. Where both an MEA and a MOCA (minimum obstruction clearance altitude) are charted along a segment of a low-altitude airway, the MOCA can be used in non-emergency circumstances only within 22 miles of the VOR, and only with a clearance (approach clearance or otherwise).