She’s still not 100% sold that humans are friends. I’m hoping to convince her that the matt comb is not evil before that mat on her back needs to be shaved via vet. Especially since I get at home vets for her which costs an extra 100$ but worth it to not traumatize her.

That's a premium nub there. Street value is elebenty kajillion, so an extra $100 for a vet is worth it.
Give her some lovins from me. ❤️
She allowed belly rubs in your honour for respecting the nub