Is this on the development list? or discussed yet? I realize that there are lots of more exciting stuff in development, but we probably don't need full interactive functionality here. Just a display of the firing angle and temperature would be nice. Modifying the P-MAG settings from SV isn't a priority. I can always connect a computer for that.
I can see a simple serial port function (similar to whats already there for reading the xponder or NMEA data) that reads and filters the data and outputs it on a special pin designation for the EMS display: mag_RPM, mag_FireAng, mag_TEMP, etc. We could then assign a widget to the pin same as we do for the normal pins (C37_p1, C25_p2/14, etc). I suppose some of the info like mag_MAX_TEMP or mag_VER would be more suited to INFO fields rather than widgets. The bonus is that the other electronic ignitions probably output similar data. Picking the EI device at the serial port would dictate what special pins are available or just limit it to a common subset.
I also can see you are going to need more serial ports. SVGPS-250, xponder, COMM, VP-X, P-MAG, etc. or a network/serial converter? serial port expander? serial to USB converter? or just more network capable devices rather than serial? Will the COMM be a network device?