OK, Lisa floppy drive emulation is a success! Begone, evil rotational disk drives, with your failure-prone gummed-up mechanisms. The age of SD card Lisa floppy emulation is here!
After a lot of tinkering, it's now working on the 2/5 and 2/10, for both Lisa-format and Mac-format disks. I'm able to boot the Lisa from the emulated floppy drive, and use it to install Lisa Office System and other apps to the HD, and copy apps and data files from the Lisa HD to the emulated floppy drive. It also works for Mac-format disks, when running under Macworks.
Just download some Lisa floppy disk images from the interwebs, copy the disk image files to a standard SD card, and put the card in the Floppy Emu. From the Emu, you can select which disk image to "insert", and then the Lisa sees it as a normal R/W floppy disk.
The last hurdle was realizing that the custom adapter I'd built to simultaneously connect a 400K floppy drive and a Floppy Emu was causing problems. After getting rid of the adapter and connecting the Emu directly, in place of the normal floppy drive, it's now working perfectly. There are still a few small loose ends to tie up, but it's basically good to go.
If anyone else is interested in buying one of the floppy emulators, I have them for $89 at http://www.bigmessowires.com/macintosh-floppy-emu/
Thanks,
Steve