Because that camera is fixed (does not steer) there is little advantage to connect it to the network. I would just wire the coax video (using f connector to RCA adaptor) into the camera one input and just use it like any normal camera.
You would need to change the IP address of the camera and connect the network up with NavNet to try doing anything additional. I do think it does limited digital zoom if you configure it to the network but little else. I agree that adding a JCU for this unit wouldn't do much beyond what you can do with the MFD.
I followed the instructions with in the Flir manual to change the static IP address. Set at the number provided in the Furuno instructions. Furuno instructed for M series not MD. Does that matter? TZ is seeing the IP address I changed it to, but is offering no control. Is there a separate IP for the MD series?
The MD625 is a stationary camera, there is nothing to control. Per the documentation that Johnny provided a JCU is recommended for zoom levels. Are you seeing the image over from the IP address?
The Furuno IP network utilizes the 172.31.X.X networks with a subnet mask of 255.255.0.0 so the directions for the "M" series would be just as applicable to the "MD" line as well.
I followed the instructions with in the Flir manual to change the static IP address. Set at the number provided in the Furuno instructions. Furuno instructed for M series not MD. Does that matter? TZ is seeing the IP address I changed it to, but is offering no control. Is there a separate IP for the MD series?
If you had a M364 or something similar you would get move-about controls, but for this I would just expect a video stream. As Johnny recommended, for a camera like this, going in by coax might give a better overall picture quality - in general the Furuno will only support what the camera is capable of.
FWIW, the MD625 really is a simple compact fixed view marine thermal camera, even the Pan/Tilt is locked in at installation. There just might not have been anything to control.