I just bought an X1D for less money than a Canon 1Dx Mk2. You are probably never going to buy one, which is a shame because they are a fabulous camera. I doubt that they would do anything via the flash socket as that is where the GPS plugs in. To me geo tagging is a great benefit as the catalogue just shows the photos on a map. That is great for travel.
I just can not see where your use case prevents using the mobile phone app. It is so easy that I doubt an X2D if that is what it is called will have a cable release either. You should be able to get a software system where each shot on the app moves the auto head if that is the requirement. Hardware solutions in cameras are a dying thing.
Hey Bob, it's great that you got one at a great value for you. But I need to stress that my use case doesn't match yours. I use the heck out of that 2.5mm port on my H4D and 645z, as for my Gigapan, or Syrp gear or any other robotic/motion head, that's the only way to interface the units. Works great with the H6D-100c - the only platform that takes a standard sync cable. It's the one thing that pisses me off about the XF platform - the non-standard cable release.
Here, I'll share what I pitched to Hasselblad for an advertising campaign: Hasselblad returns to Space. Do a helium balloon launch of a pair of X1D's doing cross shots, with a few GoPros to catch video. To do this requires an intervalometer for each camera, and that sync port is more likely to work all the way up and back, unlike any type of wireless remote.
Fancy software is nice when you can touch/kick/reboot it when things don't quite work. But a cable release more or less is going to keep working long after your phone has decided it doesn't want to connect anymore.