I've tested the difference that 1.5g of metol makes. i'm not speculating nor am I saying it necessarily does. I am saying it does because I've tested it. if I remember correctly, PE suggested that 'reformulating' ( what I would call adding a little more metol to) the developer according to the gelatin's absorbing capacity was a better approach. I intuitively arrived at that conclusion and was pleased to see PE say something in a similar vein.
Nothing personal Michael but I haven't seen any of your data contradict my testing, in particular to the issue of metol levels in bath A and its irrelevancy to contrast. i'll most definitely be continuing with the evidence I have produced in my darkroom. I invite any one to mix two A baths (a stoeckler and a thornton) and two 12g sod metaborate B bath and see for themselves.
"it says nothing about whether developer X is more or less contrasty than developer Y"
never asserted it and it has never been my concern. I made a basic assertion - more metol more contrast, all things being equal.
perhaps MrBrowning just unknowingly placed the highlights too high on the film and beyond the reach of any developer to retain tonal separation.
Michael is right for attempting to disperse any myths regarding two bath development but the op's original question was the real matter at hand.
Dave answered the OPs question about n-1...
Michael provided H&Ds
You are doing bold text instead of H&Ds... please publish your H&D.