Hi Vince,
I suspect Lotus just installed the axle spacer so as to position the drum correctly with respect to the backing plate.
Chapman probably had the rear track decided and cut a deal on the rear brakes . . and this was the compromise reached so it would all hang together.
Remember too we are blessed with hindsight.
We have the luxury with 50 years of observation to cast aspersions on this rather marginal assembly while still looking to pump 150HP through a 39HP axle . . ha.
With that said, I do wonder how many failures arose under warranty. It must have been sufficient for Lotus to update the assembly procedure.
