Lots of file explorers can "mount" cloud drives. They don't truly mount by making the cloud drive appear in the file system for other apps to access, but within the explorer app you can interact with a cloud drive just as if it were local. A good example is the X-plore file manager. Once a web storage drive is added, all of the standard features are available for use within it. You can copy/move to and from, zip, see file details like last modified, etc. Particularly relevant is the fact that you can access music and video files, and *stream* them from the remote location. Some file managers first copy files to a local temp directory, but some such as X-plore begin playback immediately, and so I assume they're streaming the files. Why couldn't the browser within GMMP be made to include access to cloud drives such as Google Drive? It would be an amazing feature. Thank you.
gmmp's audioengine and libraries work on filenames and open / read files using the File api (fopen) which only reads from the local filesystem. The engine would need to be rewritten in order to work like you are suggesting