The Fortune Semiconductor FS9721_LP3 and FS9721B/Q100 DMM chips are very similar and the protocol looks identical. Tested on a Voltcraft VC-820 (FS9721_LP3) with the uni-t-dmm driver (needs some small changes, tbd).
This is not yet fully finished, but works for most use-cases. Tested with a UNI-T UT61D using the UT-D04 USB/HID cable (new version).