Individual Cylinder Lambda

I have a client who has 4 LTC-Ds running cylinders 1-8 on an LS7. In the M1 Tune Help, it recommends having a bank collector lambda reading as opposed to averaging individual cylinders, but no basis as to why.

Given the client has already forked over for four LTC-Ds, I'd rather not sell him a 5th LTC-D for the merge collectors if it's not a really valid reason.

Anyone have any idea why it's preferred?

My assumption would be pressure sensitivity. In a NA situation I dont think the effects will be huge but I suspect your averaged lambda from individual probes may end up a little "noisier" than a measurement from a single collector probe. In a boosted situation I find even with EMAP compensation the individual cylinder probes can read quite different than a post turbine probe.