UPDATE
It turns out this IR Repeater DOES work with the X1 Hub/system-- but it requires that the Devices it controls are correctly chosen from the codebase libraries.
Example: My TV is Sony XBR-65A9G (one of hundreds of 4K TVs Sony has made in last 5 years). Choosing either of the IR Devices that come up when searching, with that as their model number, do not work when testing the "Triggers" before doing the Add Device operation- I had to choose the generic entry in the library called "4K old TV"
Testing all it's "Trigger" test links in the App, sends the correct signals from the Hub to the IRBlaster Receiver which then sends exact signal to the IR Emitter pointed at the TV,
It's an odd situation still tho-- when I remove the IRBlaster system from the mix, put the Hub in front of the TV, and add the Sony TV via model numbers, the Hub does send the correct signals directly to the TV.
(Can't locate the Hub in my case with the TV, as the Hub is in my network closet about 15 ft away from the TV.)