Works with GxEPD library using GxGDEW0213Z16 display type.
Not GxEPD2 :-(
do not use hub but do reboot between two successive installs
hub will provide power (even unpowered hub) for testing but not enough for stable operation, which must be negotiated.
eventually i stopped getting errors about pre-load etc from
sudo kextutil -tn /Library/Extensions/SiLabsUSBDriver.kext