These are very good questions. Sadly I'm not sure I can provide you with very good answers but I'll try...
With the KO30 shear test, you take an oil of known KV100 and blast it though a diesel fuel injector at 100C to induce permanent shear. You collect the sheared oil and run it through a standard KV100 test. In theory, you could take the KO30 recovered oil and also measure it's HTHS value. I don't know for sure, but my gut feel is that the entire KO30 test makes no difference to the HTHS of the oil because shear is implicit in both tests.
Likewise, when you take a fresh oil and put it through an HTHS test, you could in theory (maybe not in practice because HTHS doesnt use much oil) recover the oil and put it once more through the KV100 test. It suspect the KV100 would, for oils containing OCP VII, be similar to the KV100 after KO30 shear.
People sometimes talk about temporary and permanent shear and I'm sure a proper tribologist could bang on about the difference for hours on end. However for me, only permanent shear is of any true relevance.
There's a lot of tautology implicit in modern oil formulation and you end up measuring a load of stuff that could be reasonably estimated from other things you already have measured. It could and should be simplified. However that's not how this industry operates. Remember that one man's necessary & justified technical assurance regime also functions as a very effective barrier to market entry, so expect things to get more complicated, not less...
