Given my local airport, I check the MH fares on a regular basis. If the flight load is low, the cheapest fares are, well, cheap. But they won't credit to any of the partner airlines (of interest to me). By the time you get to the smart fare category (which do credit), they are no longer competitive. Primary compare would be in CX V class, secondarily to UL R class.
Turns out that for the most part UL code shares using the same MH planes will be a better deal. Even if you need to purchase a positioning flight into CMB. Example BKK-CMB-KUL-PER
Related question: Dose MH award availability (to partners) show up anywhere online?
Happy wandering
Fred