Since some months I own a Xiegu G90 shortwave transceiver. It is a very nice SDR radio that offers everything that you need for a good portable QRP setup. One major thing that bothered me was that I was not able to get WSJTX running smoothly with it. Although the USB serial interface is detected as "/dev/tty.usbserial-XXXX" and I configured WSJTX for the IC-7100 as recommended, the PTT was reacting very slowly. On windows all my connection issues have been solved by using the tool OmniRig1.19. However, OmniRig does not exists for macOS, only for windows. After some time the tool FLRig got some of my attention and I tested it first on windows. It worked there very well. Then I realised that FLRig also exists for macOS and I also tested it with the G90. It works also very well now.
Here are all the configurations that you need on FLRig:
And also on WSJTX:
I hope that these findings help some other HAMs.
73 de DL9MJ, Matthias