I had posted about this in the Kickstarter comments and received a reply that was not helpful for the sync issue I ran into.
The problem I've encountered while setting up 2 X1 systems is that the remote goes into an endless sync loop, endlessly cycling from 0 to 100%. By trial and error, I found that I could force a reset of the remote holding down the two buttons at the top of the remote. The remote reconnects to the hub and successfully syncs after the reset.
The reply that I received stated to keep the remote close to the hub. It was within 6 inches of the hub while I was configuring the hub, so that was not the cause of the problem.
Both remotes seems to be okay now after the forced reset.
I don't know if it was relevant, but each time, the remotes were plugged into USB and charging while I was configuring the hub.
I'm also still having major problems with the Android app connnecting to either hub. The app finds the hubs, but when I select either one, it can't connect. I find that I have to start and force stop the app a few times before it works.