Adding an oil collector on a direct injection engine can help maintain horsepower and mitigate issues with carbon build up on valves.
I first heard of them reading a online forum "discussion" between two tuners and one brings up GAD tuning. One thing I realized there are tuners that I need to study and post a section about, like GAD and Masonry.
As I studied the build pages GAD mentions an oil separator and now I'm down that rabbit hole. Well one of my favorite channels EngineeringExplained went into it and tested them. TLDR they do work and you may want a bigger one (or an AOS) so it doesn't overflow which might be worse than not having one at all.
Adding an Oil Collector is a fairly inexpensive way to protect your Mercedes. Just like the blow off valves, lower temp thermostat, this won't actually make your car go faster over a new engine, it will just protect your engine and maintain your performance better. As it is assumed the carbon build up from DI can lower horse power. Diverting oil into an oil collector can or an air oil separator oil from going back into the crankcase.
Air Oil Separators are Different than Oil Catch Cans
The oil catch can you have to monitor and empty but the air oil separator takes the same goal but a different operation. In the air oil separator there are baffles to separate the oil and air. The oil is put back into the oil system, the air back to the intake. This system in the video also uses a coolant system which will help the oil apparently not cake (according to the video).