As no one has replied, I’ll help as best I can.
I’ve looked into this a few times, the reports are that the X-King is a really good XC tyre… when it works.
The sidewalls are really thin, there is an anti-mould coating on the inside which needs to be removed with IPA before they will seal – and even then they will probably not seal that well – but they might.
I’d like them to be good, as they look like a nice volumious tyre – but £40 on a tyre that’s gonna rip, or be useless tubeless is a bit of a deal killer for me.
Rocket Rons are in the same arena as these, and are brilliant tyres – tubeless easy, and I’ve yet to rip one – but my missus has ripped two. If you’re not a clumsy rider they’ll be fine. (Not that my missus is! she just didn’t seat them properly and the bead came away with wear).