I don't feel like I'm appropriating a trans identity.

Mostly because I don't identify as trans, because I don't plan or want to transition in any sense (I've been mentally working to stop gendering myself for a decade and have made communities that see me without too much gender). For me, realizing nb was a thing was a gateway to find people who felt the same way about the gender binary as i did.

Not all enbies are like this. Some transition - socially and/ or medically. Some feel more at home with a trans label. This should be okay. Transitioning away from the gender you were assigned at birth is a transition.