Have you observed the value of the long term fuel trim in your cases - I think this factor is (also) multiplied on the full throttle map.
On a mbworld tread the guys with their 32/55 have far less lean issues https://mbworld.org/forums/c32-amg-c...ml#post2694311
(With moderate pully you possibly don't even need a tune (... of course - your ratios are not moderate).)
But these MB-C-and-E-class-guys normally don't have the big intake manifolds. You possibly especially need a tune for the big imfs. (And of course for better timing and safety when map-sensor fails.)

Stefan SLK32AMG
Leipzig Germany