Solution
I much prefer using native collision detection than trying to do it manually. This is how I did it:
Create two bones for the attached object. One small just as an attachment point, and a longer one for the body of the object.
Create a Physics Asset with a Physics Body for each bone. If the editor complains about the attachment bone being too small to create a physics body, just set the minimum bone size parameter to 0.
Set the body bone to physics->simulated. Enables physics-driven collision detection.
Set the attachment bone to “kinematic” (i.e. physics disabled) so that it moves with the parent like a physics-disabled object instead of falling on the ground.
Select both Physics Bodies in the Physics Asset Editor in the skeleton list panel, right click, choose create constraint between selected bodies. Lock up all the translation and rotation, should be 6 boxes to check lock on. This anchors the simulated bone onto the kinematic bone to make the entire object rigid and kinematic in movement.
Click the Physics Body of the simulated bone, go to the collision section in the details panel, check Continuous Collision Detection to activate it. This is critical to enable collision.
This works fantastically, you’re a lifesaver- been trying different things all day and finally found this.
You’d think “let the player hit enemies with a stick” would be trivial, but no.