I have yet to try these new Shimano derailleurs, but reviews I have seen seem to indicate that that amount of chain slap is a definite step backwards.
I am inclined to think that the damping added to the suspension system by a derailleurs is fairly minimal compared to the actual forces involved, and worth the trade-off for systems with a reasonable amount of chain growth.
Would love to see some of the 3d models showing how this all fits together.
I do like how modular the shifting mechanism is in SRAM levers. I’ve seen aftermarket parts available for these sort of 10-11 or road11 > mountain12 swaps. Also easy to remove whole shift mechanism for 1x or singlespeed setups.