What's the proper way to override new-category.js groupPermissions()?

Where should the file go? Isn’t it under my_plugin/assets/javascripts/discourse/routes/new-category.js? It doesn’t seem to be changing the default group to admin (instead of everyone) as I want.

(I want to disable the part where it checks that the groups of the child are also in the parent, since my plugin will put all the child’s auto-created groups in the parent as well, but I can’t find where I can override this, so as a workaround I’ve put admin group in parent, and want to set admin as the default group of the child instead of “everyone”)

This might not be of help, but perhaps rather than not testing (and then have the back end at them) you instead have it automatically add them, which seems like a good idea for core anyway, if I’m understanding.