I spoke to the park man today at his office for 30 minutes today.
On August 1 2014 The one day permit was changed. It is now only a half mountain hike. People's passes will be inspected to make sure they don't go beyond the 4.5Km point. (the reason given, 80% of climbers were failing to reach the top and people were too often delaying the 5pm closing time)
Pushed for time - You can buy a 2 day pass including the accommodation. And if you make it up Low's pass before 10am the inspector may give you permission to go onto the summit, so that means you should be able to get to the top and out of the park, but you've paid for a bed you don't use.
You are advised to book well in advance as the top lodges are almost always fully booked. However I often meet people who manage to get a bed within 4-5 days of booking. (this maybe cancellations or possible extra beds being help back). The situation is not likely to change there is only the Sutera 150 bed Lodge and the Via Ferrata lodge 40 beds (the ones used by Jack's). The bottle neck is that there is not enough water supply to the lodges, so the situation won't change soon).
BTW people have problems with the public minibus from KK town centre. I waited from 7 am to 8,30am yesterday for the bus to leave, same for other people on other days, 20RM/90 mins . Next time I'd try taking the regular minibus from Shangri-La Hotel to Inanam and pick up the regular big buses running to Sandikan from there.
