What is a good value for cell 21? What AFR should I see on the WB in decel (but not during DFCO)?

With my 98 F-body and using the stock VE I have -8% LTFT in cell 21 and an AFR of about 13:1
This with a MAF curve that gives me +/- 2% LTFT on the other cells.

If I change the decel VE values (low MAP range) I can adjust cell 21 to +/- 2%. AFR still remains 13:1 (?)

There is a big differece between the C5 (97-98 years) VE table and that one of the 98 F-body.
The C5 has about 20% less VE values than the F-body: this could explain why you see +8 with stock VE values and I see -8

So back to my question: should I see about 0% in cell 21? Does it matter?