It's not in the list of supported sets, yet, but does not necessarily mean that it won't work. But you may have to do a bit of work to make that happen, if you choose to go with that set. https://www.3cx.com/sip-phones/
Come to think of it, I'm not aware of such a model existing on their website other than an obscure reference to an X4SG which does not appear anywhere on the product pages.
I'd say stick with supported models just to be on the safe side.