Thanks! Finally Ii got it working.
There was a number of issues, first I hadn’t realised that “object type” and preset were two different things.
So I set the collision channels correctly according to types, but still couldn’t get it to collide with the character mesh.
But that turned out to be due to the collision of the mesh only being active during physics simulation, enabling per poly collision made it possible for the PHAT to interact with it otherwise.
I’m sure there’s a more efficient way and make use of the character’s PHATs collision primitives though.
The asset also jerks around quite often, but I think I can get rid of it with some tweaking of its settings.