hydroxylapatite augmentation is a bad idea all around since it leads to uneven absorption later in life.
maybe this is certain forms of hydroxyappatite? for example AG use heated grafts that fuse with the bone, they don't absorb i dont think. at least i wasnt told they do. and even if it does lead to uneven absorption, it doesn't alter the texture surface of the bone (lumps, holes, crests, etc.) so further augmentation can be applied later if desired.
but im not sure how effective hydroxylapatite is in combination with upper jaw surgery, since moving the jaw forward usually necessitates hydroxylapatite. it is part of the upper jaw surgery, in absence of it the mid-face would look caved in. so the end result might not be a huge change pre-op because it is more designed to maintain features - my guess at least.
also have to distinguish what area cheekbone. if your malar cheekbones are already low, the hydroxyalapatite is unlikely to raise them. just move the cheekbones forward horizontally. likewise it might be difficult to widen the cheekbones if they're already small to begin with. hydroxyalapatite can only be applied to existing bone i believe. if the asymmetry extends from top to bottom on the cheekbone, hydroxyalapatite wont do much. that might require a stronger augmentation, probably grafting or an implant.
technique probably plays an essential role too.
