Since nobody answered so far I would like to give you my opinion:
It is not a good Idea to split up if there are only minor tweaks between projects. A way forward is to have a common core library - you need to do bug-fixes only once and not for each branch. Then have sub-repositories which are specific for each project and only using the common core.
Also if you put each project in a separate repository its hard to compare revisions as this is not supported from std. tools like TortoiseGit.