Update: installed the driver from here:
https://github.com/adrianmihalko/ch340g ... l_V1.3.zip
I now have duplicate serial ports (/dev/cu.usbserial-1420 and /dev/cu.wchusbserial1420), but uploading works. It seems like maybe the built-in Catalina driver doesn't work with this board yet.
The output with the built-in driver is below:
Writing to file /var/folders/dr/l7mlbx6s1wb061grlnkgpykr0000gn/T/arduino_build_910253/sketch_nov28a.ino_Wired_OTA_blob.bin
Image from 0x0 to 0x18640 will be loaded at 0x20000
Connecting over serial port /dev/cu.usbserial-1420...
Sending Hello.
No response for command 0x00000000
Failed to respond
Fail
Sending Hello.
No response for command 0x00000000
Failed to respond
Fail
Sending Hello.
No response for command 0x00000000
Failed to respond
Fail
Tries = 3
Upload failed