Very helpful information Frank, thank you for taking the time to share it.
I already have the OS Giken 1.5 LSD fitted so I guess that's one less thing I have to worry about!
All things considered, I think I will have to compromise and go with 35 profile tyres on the rear. Reason being; I need at least 295s at the back in order to put the power down and sadly, no mainstream tyre manufacturer produces readily available tyres in that size with a 40 profile. So, in the unfortunate scenario I suffer a blow out or the tyre sustains some sort of irreparable damage, I will effectively be at the mercy of an international company, which will undoubtedly leave me stranded for at least a few days whilst the replacement tyre is shipped, at an extortionate cost no doubt, due to the urgency.
In the ideal world, and as I have eluded to in the past, I would prefer a larger side wall at the rear, for the various reasons that you and I have catalogued previously; however, this world is far from ideal and that is why I think a slight hit on the rear profile would be worthwhile. Going to a 35 profile from a 40 profile, is in the grand scheme of things, a relatively small change. This will not only afford me the luxury of having Michelin Super Sports as an option for tyres all round, but also allow me to stagger the front with a 40 profile, a stock feature I would have always wanted to keep proportionate.