When garmin moved from the 430 to the 650, they used the same 78 pin high density DSUB connector for the main side. They could have easily used the same pin positions for an easy upgrade - but we need kabuki theater to make sure avionics dealers charge 50-100 percent of the cost of avionics to collect their service fees.
They added a p1002 connector, a 26 pin high density connector of which 21 pins are used, for Ethernet. The com connector still uses 10 positions but hey - let’s move to a 44 pin high density connector. It’s not like we could use the same 15 pin connector for those ten.
On the nav side they moved from a 44 pin connector to a 62 but oh no. Let’s charge our users 50% of the retail cost of the hardware to have it installed.
Garmin is odious. Decent product but entirely too overpriced /overinflated and predatory for my taste. They knew full well after Avidyne that there was a market for plug and play upgrades but they didn’t give two craps about the customer - and here we are