Please correct me, but as far as I know it wasn't Linus Pauling who advised on CoQ10, but Owen in his book with additional therapy enhancements.
I made the funny experience when starting CoQ10 about 9 years ago, that above 150 mg/d would cease angina-like chest-pain always present with some stress (physical or mental). Then I found out about half that amount of Ubiquinol had the same chest-pain eliminating effect. That has hold true for me since, with the only difference that if I drop below these doses, chest-pain come back, now without any stress. Though haven't heard of an other one reporting that same effect of Ubiquinone and Ubiquinol as in my case.
Also to test CoQ10 in serum only total was accessible to me. However, for more precise dosage information heard the ubiquinone/ubiquinol ratio (CoQ10ox/CoQ10red ratio; optimal ~9) would be more telling.