To answer your earlier inquiry... in general it should be safe to use both. When paths are passed in plugin configs, we run them through path.join to remove relative relations and double slashes, etc. In all cases (exceptions are bugs), the path should be relative from the plugin directory itself.
Actually it was an update pushed in the last couple of hours which have solved the issue. At least on one of the plugins which I have tested. I hope it will be the same way on all the plugins. Thanks for your help.