This is definitely still a great forum and I note the entire forum has about 33,000 members which is astonishing. Especially because the knowledgebase of these members is very high.
The last made Digital Ensemble was the PR804. I think they are incredible and I aspire to own one someday. A picture of it is featured on the front of my new site at the moment at https://technicskeyboard.com
Sadly, none of the digital ensembles ever had SD Cards. It is possible to add one but it would be an emulator (emulating floppy disks in the same way that the USB emulators do).
If I ever have one I will be very interested to take it apart and see whether the electronics are in place to add the KN7000's SD card to it. Doubtful but possible. When you look inside some of the keyboards, connectors are in place for various extras. Sometimes the circuitry is there but the components aren't. Anyway, I'm pretending to know about electronics, which I don't.
Posting another message in a min.