I just found this in the 2007 Lonely Planet to Malaysia.
"A guide is only compulsory if you intend to venture beyond Raban Lata, ie to the Summit"
We do not have the accommodation at the Raban Lata Resthouse but I wonder if we
simply can hike to Raban Lata and back in one day without any permits, accommodation.
and wonder if anyone has any experience with this, comment or ideas if this information is correct.