At this time it is not a data box option. I can pass this information over to our Product Development team and see if that is a feature we can add with a future software update.
If you have the SCX20 on the 2000 bus, the MFD will not send out heaving via 0183 so you would require the IF-NMEA2k2 to convert the 0183 data for your GP39. (which will convert and provide heaving information)
It was just an example, I want the TZT 3 to be able to be displayed on the screen in this way.
Therefore, it is worth working on it with the new update to TZT 3 .
I am not using GP39 .