HDDs automounted erratically get trailing "_" (underscore) or not as /media/... path

The links didn’t have anything to do with samba. There is a mechanism in place whereas a drive that is plugged in and not manually mounted gets automatically mounted to /media and the mount point is preferentially titled the same as the drive label. If something happens and a mount point or folder exists in /media using that name then the mount point will get a different path. What I was suggesting was to manually setup an autofs mount point for your drive to /mnt. In this way the mount point will never move and additionally it does a better job of mounting and unmounting drives. The second link was a quick and easy way of telling Kodi to look in a different file path so you can make a change such as this without needing to rebuild your library.

But speaking of samba if your sharing your media to other devices using SMB and you switched to a manual mount point them you would also need to manually configure a share for this new mount point. The automation script that adds samba shares to auto-mounted drives doesn’t touch manual mounts. If your sharing your media via UPnP then it should be a non-issue.