Good theory, but the law works on specifics. There are general, overall type rules, and there are more specific rules. The specific rules will be applied in preference to the overall rule.
In other words, you may not exceed the overall height gain allowed, but the specific rule about tyre sizes will be applied anyway.
As per my car, my height is on standard albeit sagged springs, but I am still technically illegal because the tyres I am running exceed the maximum allowed without examination and approval.
This is the info I have received from my dot anyway.:p
Cheers
Kev
