The MAXLIFE, Complete, and Valvoline Restore and Protect use the same base chemistry but contain different detergent packages based on what they are marketed to do. For example Valvoline Restore and Protect has the strongest cleaners and most lubricants to get the ultimate clean for deposits and help increase MPGs. MAXLIFE has less of the lubricants, but more cleaners and actually a "keep clean" agent that helps deposits stay off of surfaces once cleaned. The complete fuel system cleaner is the "good" in the Good, Better, Best lineup. We suggest pricing to retailers... they dont always follow it. How we want it to be is Complete (under 10 bucks). Maxlife (around 11 bucks), Valvoline Restore and Protect (around 12 bucks). Again, we suggest... but retailer sets it where they want. Long story short Valvoline Restore and Protect is going to give you the best all around chemistry to clean and protect, while also having a friction reducer to also aid in MPG gain and help reduce wear. The other 2 additives are targeted for someone either looking for a budget friendly, but still great cleaner (complete) or something targeted specifically for high-mileage (MAXLIFE).
There is still no special fuel system cleaning sauce to clean the back of GDI valves that are not aided by port fuel injection, unfortunately. While yes, to your point if there is some overlap in timing you may get some residual clean, but nothing we would say is measurable. For an engine with direct injection only, the best way to keep valves clean is to continually add an additive like the Valvoline Restore and Protect fuel system cleaner from new (getting the average person to understand that and actually do it is tough)! If they were to do it the cleaner burn of the fuel and reduction in deposits would help keep the valves clean much longer.
The testing mentioned above (ASTM D6201) is done with a Ford 2.3L 4 cylinder engine by an ASTM certified lab, not a direct injection engine. This is the industry standard to evaluate how well an additive prevents Intake Valve Deposits. They also use this for certification of top tier fuels.