CIFS Document Provider allows mounting SMB, FTP, etc. (no NFS though, I dont think there is an option for NFS on Android) via Android's Storage Access Framework (SAF). This allows viewing network shares in the AOSP file manager which comes with GrapheneOS rather than another crappier file manager. The AOSP file manager is also used as the file picker for most apps, so it is also infinitely more useful than an alternate file manager in that respect. Ive had great luck with it so far, it really is far superior to any other method of accessing network shares.