2. The X-1 Receiver:
The receiver is not a TTL receiver even thou it has a TTL hot shoe mount. The receiver is just to allow you to assign it a group, a channel and a firing signal. This aid if your using a non X-System strobe and flash to be in a group/channel and a firing signal.
I'm sure this is just some confusion with the wording, but reading this I got the impression that "the X1 system doesn't do wireless TTL because the receiver doesn't support it"--which is false, of course. So, for the record, the X1 system is a TTL-compatible system. (Or it's done a great job of pretending to be one...)