Hi Dave,
Don't you think A will have a broader optimum, with two unequal offsets? (given MJ King's modelling) Or you assume that simply more pushing power at the optimum offset is more important/effective?
Oh, with a pipe construction it is easier to make a TL with two woofers using an identical offset (very small), but if you make wooden/MDF cabinet, two different offset might even be easier. I have also seen design, basically using two separated TLs with slightly different length/offset.
Best regards,
Caratje