Allow apps to output to a paired phone's file system.
I just had a dev ask me for logs after a crash but when I said I was on a Quest they informed me it wasn't possible to retrieve logs on the Quest. Since people pair a mobile device to the Quest, why not make that file system accessible to devs? Then they save a copy of the log to your phone so it's easily accessible by the user.
This could also be useful for browsing media from your phone on the Quest.