Is the USA Moto X Pure missing the hardware for dual SIM capability?

I noticed on my Moto X Pure (USA) that the SIM tray looks like it would support 2 SIMS + Micro SD on my SIM tray, but one of the SIM holding slots is covered with plastic... Is Motorola artificially limiting dual SIM in the US? I wonder if the internals in the phone itself has the hardware for supporting 2 SIMs and it would be possible to modify this SIM tray to hold 2 SIMs or import a SIM tray from a country with dual SIM models? If the ROM on the US version wouldn't support it, I am sure a custom ROM could be made to support it (if my theory is correct).