Since it looks like we will have some development in these libraries this summer (whee!) I propose starting 'develop' branches for these libraries. The mentees and others can then create feature branches off of develop, and submit pull requests for feature branches into develop. Then develop is merged into master periodically when all is clear. That is the typical GitHub cadence as I know it anyway. I am very used to this pattern and will happy to be the person making sure it happens.
So, perhaps interested parties could vote, if it goes ahead I will write the ticket, then create the develop branches.