OK, sorry for the jerk-knee-jerk reaction. It just sounded like...well an arm chair response.

I can't honestly say I have ever seen this application before (automotive). But they are commonplace in large flow/volume vacuum systems. No, not Electrolux. Kinney and Roots systems places them in all elbows to increase efficiency and reduce drag for pumpdown times on large semi-conductor process chambers.
I recognize the need for taking any restrictions out of the way, but it looks to me as though the inside diameter of that elbow is ~ 3.5". Area~9.6 in sq. The cross section of the pieces removed (at a guess)
looks to be .064" thickness by 3.4" (times 2). .4352 in sq. about 5% of the total area. A restriction to be sure.
But does it overcome the gains that the baffles provide by steering the air in a more even pattern?

I don't know. I would like to see all of these surfaces polished. It did wonders for the aircraft industry.

Looking back, it seems like a few other members recognize them for what they are and what they do.

It looks like my trying to help is causing more problems than solving.
I suppose can just read...