Reading the comments on the issue you created, it appears the plugin author has helped your confusion, both with regard to Compare coming pre-installed or not (which it doesn’t), but also regarding uninstalling it.
But for those who don’t follow links to the issue boards, the short version:
Notepad++ does not come pre-installed with ComparePlugin or ComparePlus plugin. It is safe to delete D:...\Notepad++_portable\plugins\ComparePlugin\ (as long as N++ is not actively running when you delete it), and it will not in any way, shape, or form mess up nppPluginList.dll. Not noted in the comments: the nppPluginList.dll essentially tells Notepad++ where to download plugins using the Plugins Admin interface; and while it does read the N++ plugins directory to find out what plugins and versions are currently installed, it doesn’t care if that changes outside its control.There would be two plugins in the Plugins menu, and each would set up its own toolbar buttons (and I’m not sure you could tell which buttons go with which plugin). And if you used the ComparePlugin comparison, it wouldn’t work right in Dark Mode (see here for a recent issue about that) the two can technically coexist, but you would just always have confusion over which you are using. the intention is to only have one of the two plugins installed. (And since ComparePlus was released, the intention has been for users to uninstall ComparePlugin and just use ComparePlus.)What happens if I install “ComparePlus” without “Compare” being removed?