I hope I haven't misunderstood your comments...

I left the entries in config.php as examples.  If they are not configured (as they currently are) then the ternary if on line 73 of index.php sets it to a default of '/files/' as is used in the current version.  If we were to remove the changes in index.php then the Paths, filemanager_path setting would have to be mandatory.

There is no need for the comments ref slashes as the ternary if in line 73 (again) trims any slashes from the entered value.  So regardless of whether any slashes are entered, they will all be stripped.