This looks like a really nice solution for easily handling updates for GitHub hosted plugins. I have a couple of plugins on my site which are hosted there and I end up upgrading them once every year or so, which is not the best :/

I suspect (but am not sure) that it will break with plugins that include submodules or use an abnormal folder structure (some GitHub repos include the plugin folder itself rather than putting everything in the root like WordPress expects). Anything using Composer will probably fail too.