So, this proves that the driver supports standard cassette files. However for actual driver defects you could talk to the original author who I think is Kale. Remember, the systems are all marked as NOT WORKING.
I think I have almost nothing to do with bmlv3 as per now. And hey, somebody should explain to me the reason behind "bml3mk2" / "bml3mk5" romsets in the driver -.-"
