There are many crucial outstanding issues in the queue, at least for 7.x.
I am applying for co-maintainership so that those can be committed. This is important to me since I am the maintainer of the 7.x branch of the Salesforce API module, which strongly recommends this module. I would have difficulty recommending people use the 7.x version of this module in its current state.
If accepted, I wouldn't be doing anything beyond bug fixes for this module, and only for 7.x.