Just got back from some quick function/ammo testing. 90 rounds total, half of which were 115gr Blazer Brass and the other 115gr Barnaul. Tried a few magazines of each, and then mixed a mag with both manufacturers... CX4 had no problem cycling despite the different lengths of the two bullets. Think I'll stick to Blazer Brass though, seems to be less dirty and more accurate.
As for lubrication, I decided to use some 'Super Lube' PTFE grease alongside the bolt rail and where the gun splits in half. It held up great and the action is as smooth as can be IMO. So I think I'll continue using a combination of that stuff and G96 for lubrication and cleaning.