We have set up a zoom call to bring in a "remote guest" for studio shows by using a seperate adjacent laptop and the NDI screen capture to send the video feed to the TC-Mini-HD4. The home viewer sees our stage show with a variant of the zoom call as the on screen guest, usually a 2-up picture in picture. To avoid audio mixed signals, we send the headphones out of the laptop into our audio board as part of the stage's master audio mix. To route the audio back to the zoom guest, we send them a mix-minus from our audio board via a 3.5mm patch cable through the laptop mic input port.
As an added feature, on the laptop, we use a $40 HDMI to USB dongle to capture a video feed from an auxiliary camera specifically used for the stage view. This is only for the zoom guest, however, and merely adds to the zoom caller's visual experience of our hosts and unnecessary for the production itself.