My gf and I recently went to Borneo with BA and MH. AIUI there is just one MH lounge in the terminal used for flights to KCH, and it was nothing special, but a nicer spot than hanging around by the gate. Note that it (and the whole terminal) is dry.

Prior to BA34 we visited the CX lounge, just as it emptied out. It's OK, but I wouldn't bother going again. The MH F lounge I thought was fantastic. Waiter service throughout for drinks; excellent showers; good a la carte food. We popped into the J lounge because it has a smoking room – while the other half had a vape, I wandered around and thought it seemed like a cavernous shopping mall food hall!