Can't get 59.94 refresh rate on a Mac

Our current setup is a Windows box running ProPresenter connected via HDMI to

1. Decimator MD-HX (primary output)
2. Black Magic HDMI->SDI 4K CONVMBHS24K (stage output)

and both have SDI runs to the ATEM ME/1.

The windows box shows a refresh rate of 59.94 fps and generates a stable signal to the ATEM via the converters.

We're replacing the Windows machine with an iMac Pro. The iMac Pro only has USB-C out, so we're using two Anker USB-C to HDMI (A8306041) to make the HDMi connections.

Unfortunately, the iMac only gives me a refresh option of 60Hz and not 59.94Hz. Any suggestions on what can be done to get the Mac to show the 59.94 refresh rate? Is ScreenX the only alternative?

Update: I forced the Decimator to scale from 60hz to 59.94hz. Would much prefer to not have to scale but this is a decent stop gap for one of the displays.

is what it is.

or switchresx works for me.

switchresx wouldn't show the refresh rates for me either. Can you manually enter the refresh rate if it isn't listed as a supported option?