I've been hedging about whether the FF would be worth it, but I just spotted an ad for a red dot scope someone had on FB, and it reminded me of crazy setups I've seen of people mounting a camera with a scope to one side, or with the Q's for birding, etc.
There is very little stopping anyone from simply mounting a hunting scope to the hotshoe on the new FF so that you can simply go out, aim at whatever spot of sky you want to, and, well, shoot.
With the need for the O-GPS1 eliminated, it frees the hotshoe up for whatever. In this case a bit of creativity that would shave a stupid amount of time off setting up for astrophotography.