Pretty sure they can also weld on a thread cover and make it kosher with sporting rules too, but perhaps not...
With rifles, there are a bunch of sporting requirements. I'm not quite sure with this weapon's construction that it would be cost-effective to try that route... But then again, maybe it would.
As for the CX4 carbine, bear in mind it uses way more polymer than I'm personally comfortable with -- including a polymer hammer! I priced it out once and it'd be ~$250 to get the internals to a similar military grade parts, internally, as the EVO, which means they cost the same before accounting for that the CX4 will likely never offer a replacement stock, and needing to thread the barrel, etc...