SPI logic implemented:
radar、WMD、HUD designator in point/area track mode, will set SPI for WCS.
these 3 'sensors' are exclusive, any one of them set SPI, will command the other 2 to break lock.
if none of these 3 sensors set SPI, you current wpt became SPI(default UFCP page, line 1, number right)
wpt#40 is reserved for WCS SPI.
if there is SPI set in WCS, WCS will rewrite wpt#40 coords.