Ok..I was in the garage earlier and set it all up on the bench. The two units do recognize each other. I can not send the Navionics Vision+ maps from the 923XSV to the 741XS. I do think I could have viewed the G2 Vision card on the 943XSV since it was an option but I didnt do it. I just wanted the Navionics stuff to go to both.
The 741XS is a used unit that came with the boat. I attempted to update the software but was unable since it was registered to the PO. I opened a chat with a Garmin tech and he said he would start the process to reach out to the registered owner of the 741XS and if there was no response within 3 days they would send me an email to re-register the unit in my name and then I could do the update. I then asked him about the displaying the new charts on the 741XS when networked with the 923XSV and he said it would not. I will take that as a no and a no from Garmin and my own attempt.
The next question is do I sell the two 741XS and buy another new unit?
Retain the two 741 units and still network them and use the 741s as displays for the Radar and maybe autopilot control and other things like camera display, Fusion control?
I am leaning towards just getting another newr unit. The 923XS was not as big as I thought it was going to be. Maybe need a larger screen.