How do I manually add trackers to a face that won’t auto track?

I have a working test case, and I can map metahuman trackers to a normal face. However, I am going with something more non-uniform, more like a skull, that doesn’t have clear/normal facial features that the auto trackers pickup up on. I want to manually add them. (I realized I’ll have some tweaking to do on how the facial performance looks, since it’s not exactly uniform). How do I move forward?

Thank you, any input or workflow ideas are super appriciated!