django-oauth-toolkit - provide application access to specific model

Question

I have a concept of Slack's workspaces in my app and I'd like my consumers to specify to which "workspace" they are installing an app.

Even though I can see that I can extend an Application model, it doesn't really help.

Is there some best practise I could apply here? I've read the documentation several times. I was thinking of the following 2 workarounds, but there must be a simpler way for this.

1) First let user to authorise an app with his account and later let him to apply it to the workspace simply by creating some model and checking this on API/view layer. The problem here is that user experience is not as smooth as on Slack or Github where you select what entities you want an app to have access to when approving an app.

2) Extend Grant & Token models with a reference to a Workspace. In that case I'm struggling with adjusting forms, since I can not override them in a settings. (I can do that for models & templates).

Do you maybe have some idea how to do this? Thank you