Hi Martin,
happy to hear that you can make use of all the 192 slots
Yes, SysEx transfer is only possible as of 1.03.
It should not overwrite any patterns at all when you perform the update.
Personally, I would record the output as midi on the computer beforehand, just to make sure I at least have the midi data if something goes wrong. Maybe you can set up a pattern chain from 1 to 192 and just let it run, while recording the output.
I donĀ“t think anything can go wrong when updating the firmware, but if 192 patterns are at stake I would be doubly careful.