Since what is actually mounted are partitions, not devices (although some older pendrives may not have a partition table but the device is treated as a partition anyway), vl-hot in the more recent incarnations looks for a volume label and uses that as the mount name. If no label is found, it defaults to vl-hot, vl-hot1, etc. I looked into using one of the USB device strings for this a long time ago, and it is certainly doable, but they are not always "nice" names, so went for the labels instead.
EDIT: The new naming convention in the latest releases makes it possible to default to /mnt, but I would have to rethink vlh-umount which relies on a specific dir for unmounting all vl-hot mounted partitions.
EDIT2: BTW, there is a bug in the user selection code on the latest release (already fixed on the svn repo) which causes a failure of the notification popups in many cases.