The receiver design is a modernized updated 55X, but the overall "architecture" is convoluted.
It is a direct transplant of SG55X operating ( gas and locking ) system. Everything looks like a direct copy. What they do was throwing away the outdated(expensive) way of making receiver out of heavy sheet steel and welding the locking block on it. Instead, they fix the steel locking block and trunnion to an aluminium extrusion tube. This is basic idea of how all the current designs are executed, from SCAR to MCX, whether the steel trunnion or locking block is affixed by two cross bolts or other more permanent method. Actually, the Bushmaster M17 was already using the concept back in the 80's.
Instead of making a new shorter trigger housing with bolt catch and , which SIG/Swiss arms did when re-developing the entire AK concept back in the 60/70's, the M10 sticks with the AK receiver blank to use as the trigger housing and the basic design of AK trigger group. It is probably conceived to be "cheaper" for them to use AK blanks without making a new lower trigger housing, but the entire upper design is now driven by the desire to use an AK receiver blank as the trigger housing. To make that work it turns into a rather awkward non-push pin receiver / trigger housing arrangement ( the AK blank is probably too thin for push pins, so the cheapest way is to make it permanently attached and only crack opens) . So it is like the wagon is pushing the horse here, they built a new rifle on an AK receiver blank that was designed to work as a receiver, but now it is only used as trigger housing. So what is the point of sticking with a rather crappy AK like trigger housing? If you go that far may as well do what Sig/swiss arms did in the 60/70's, design and make a more ergonomic trigger housing!
I think it appeals to people who want the "AK" look and the mediocre "AK ergonomics", in addition to the NR status. It is also a bit of a forbidden fruit for Canadians because we cannot own AK. But putting the NR status aside, which is the major appeal in the Canadian market, the philosophy behind the system is quite convoluted. The rifle is redesigned/rebuilt around the most antiquated part of AK, the square box stamped metal AK receiver, just because! The end product doesn't even need the AK receiver, other than for the reasons of availability of mass produced aK blanks and the "look"!