agreed. oculus introduces a strange almost flange to ambisonic files. not sure if it is something to do with my setup, but i followed the steps here:
https://forums.unrealengine.com/development-discussion/audio/1426838-how-to-setup-ambisonics-playback-in-4-19
hrtf seems ok, but not super impressive. have you tried resonance? if you enable spatialization and reveb plugin under project settings/platform, ambisonic playback and hrtf feels pretty good right out of the box.
to get resonance’s occlusion you have to do a build of the engine, but upon testing that, it seemed equivalent to built in.
resonance, as dan said, is intended to be lightweight, which makes sense if one of its targets is android.