ronnie, i can tell you on this route what you say about VHF coverage is utter crap. Generally speaking you bisect Koror and the Philipines and you are at least 400miles + from Manila and not withing a bulls roar of Manila Control on VHF. Transfer to VHF is after talking to Naha on HF, then around another 45minutes to Tokyo on HF, finally followed by the last 1hr 30 minutes odd on VHF. You are lucky if you can even talk to Manila on HF for the whole 3 waypoints you pass through on a tiny triangle of their airspace!
4 hours VHF coverage on this route....ha! NOT