The issue with Hexbear is that their users tend to talk in a very demeaning and insulting manner. About half of the popular posts on Hexbear are about making fun of people or communities. Their political views are less of an issue; it’s more about their toxic behaviour.
Do you see instances who’s main purpose is to represent “people inside the more mainstream American Overton window of mid right to far right” that are even nearly as popular as Hexbear?
If you’re browsing
all
you frequently see posts from Hexbear users. I’m yet to come across a noticable amount of posts from users from an instance which represent the group you mentioned.(I couldn’t even name a single instance that fits that description, because if they exist, they’re not nearly as active as Hexbear.)
Toxic people exist on all public instances. But on some they’re more common than on others.