I spoke with MMS Support and this is their reply, hopefully this will clear up some confusion with how the can is ran and how it operates.
-for our pcv and draft can the tops are exit only, if the top would allow air in the whole thing would not work, agreed
-the stock / gutted pcv is in the same valve cover (valve cover does not know what side of engine it is on) and doing the same job as before, just relocated because we have the can on the pass side.
with our pcv can this line can be restricted and or even one-way check valved as ventilation OUT this side of the pcv system is no longer necessary, but provided the main air filter is appropriately sized and resonably clean, suction here that would pull on this cover is usually negligible (much like how this hose when near stock power and on passenger side also stays clear and dry)
-our draft and pcv can LOOKS like it is the type that can only be run one leg to each valve cover, but that is only how our RACE model works. draft is in-line filtering with pressure release (exit only) two chamber can, and pcv is the same with integrated pcv control and boost/ backfire protection. the race can is single chamber.
it looks different and hooks up different because it IS different
Ok. That makes more sense. Their breather is like the CFM breather with the check valve. It allows vacuum to pulled under part throttle and vents under boost.