Although you have split out many of the plugins, many still remain in the main repository. It would be good if these were placed in their own repositories but linked via a git submodule. It would also be handy if the already split out plugins were also linked.
This is helpful because for automated build systems, you can deploy and test all code at once or exclude the building of submodules. please see: https://www.benday.com/2016/11/04/one-tfs-build-multiple-git-repositories-with-submodules/ for an example...