Are there any limitations on re-installing the full MinimServer license?

[simoncn]

The full license allows you to install MinimServer on up to 3 devices at the same time.

If possible you should uninstall MinimServer before you reinstall the OS. If you don't do this, you might be left with an unusable license activation for the uninstalled OS that counts towards your limit of 3 installations. There is a way to fix this but it's simpler if you can uninstall first.