Brad is right about it being a tech issue. There are some oils that do contain performance enhancers. There are also some that while they do not contain enhancers, they mimick enhancers and again, make tech very difficult. Open oil, like open fuel, makes a mockery of tech. Why control anything if you can’t control fuel.
If we are serious about tech, first we have to spec fuel. The nice thing about VP is that it’s just gas, not oxygenaters of any kind. It is also very consistant. No matter where you buy it, it will pass tech if properly stored. Limiting oil to 2 types (castor and sythetic) covers the needs of most engines and makes fuel tech possible.