Thanks for your detailed answers! 
If it's a problem with the wrong forum category, maybe adtbm can move the thread? In my opinion, Xclcd belongs to Xemu and Xemu belongs to the Mega65 and ... at the end it's all about Commodore. 
According to Bitte melde dich an, um diesen Link zu sehen., the LCD should have a function to copy the virtual RAM disc to a external disc drive:
The main menu offered a few utilities for copying from the internal RAM disk to an external drive ...
I haven't study your xclcd sourcecodes, but maybe it's an easier solution (as the RAM keep/restore routine) to add the possibility of using an external disc drive e.g. as unit 9? I don't know, but maybe you could use some code from the xc65 or xmega65 who can use and attach d81 disc images? An external disc drive would have the advantages of easier exchange and use of datas between the other emulators (xc65/xmega65) or VICE & Co.
That's only just an idea which came in my mind ... maybe I'm the only one who plays around with an emulator for the LCD, which is even more rarer as the C65, anyway? So it's just an idea for the xclcd, if you feel very very very bored sometimes. 