I had a look, the ~4MB if for the base app, webdav, LAN, FTP, SFTP and wifi transfer come as separate plugins, which add roughly another 5MB using this size i found.
Twig includes those features, it also has Git, restic, s3 and jellyfin/emby support. I wanted to keep local and remote files in one tree, where you can expand folders and archives without leaving the view. I find that easier to use.
https://www.ghisler.com/android.htm