BTW. It would be amazing if "cd jh0:" worked. But it doesn't'.
The behaviour is the same as in the Photo above. "cd jh0:" gives (can't find jh0: ) and "cd jh1: (Pops up the Insert Volume jh1: ). So something is special about "jh0" when DJmount is run.
Using the info command in Amiga CLI should reveal more information on how JH0 is handled.