Add new model to strapi-plugin-users-permissions

Adding a new model into extensions/users-permissions/models does not add that model to strapi.

I want to extend the strapi-plugin-users-permissions and as part of this work I need to add a new model that my code will use.
I can extend controllers and services, I can extend the bootstrap of the plugin.
All of it I can do by simply following standard extending approach. It works as expected.
But the new model I am trying to add is not being picked up.
I reckon that is because extension only works for the files that present in the original plugin, but I don’t know where the overlaying code lives so can’t confirm.

Anyways, is there a way for me to get what I want?
Strapi devs, gurus, experts, self-proclaimed gods, anyone?

I could just fork strapi and add it there, that would work, I tried it. But I don’t want to go this path.
Or should I?