Make another probabilistic model in scvi-tools

Hi all!

Awesome work with this toolbox harmonizing the interfaces and user experience of single cell probabilistic models!
We are currently developing such a model, and have interest in implementing it in the scvi-tools framework, too. So in the ideal case, when the work would be published, it could be available through the super harmonized scvi-tools for users.
At the moment, we’d have a few naive questions regarding the involved scvi-tools contributing steps.

-Aside from coding standards, code documentation and testing, do you have other criteria on the content of such a model which decide if a pull request (PR) is rejected from scvi-tools integration?
-I did not yet completely understand the versioning of the scvi-tools package; is the general idea that this is updated roughly periodically, and the models with accepted PR in the meanwhile are then included in the following release?
-In the spirit of PRs and after glimpsing into the opened Issues and PRs in scvi-tools, would you typically expect external potential contributors such as us to to initiate this with an issue such as “implement model xyz”, and follow up with a pull request?
Best regards