Thanks Evans. It turns out that my problem was that I was mistakenly selecting "Sky Watcher SynScan" as the mount type (since SynScan is the software that normally drives it!) rather than "EQmod" which reflects the protocol of your EQdir. That little fun fact alluded me until tod...

I've been told by several sources that I can use the PegasusAstro EQdir USB Stick to allow my Macbook Pro (with either High Sierra or Big Sur) to drive a new Sky Watcher EQ6-R Pro mount. My Mac does see the EQdir cable as a valid USB serial line (e.g, there is a "cu.usbserial_#####..." ent...