Hydroforce Metering at Different Pressures

I was looking to start cleaning at 500 psi, but when using a hydroforce dilution ratios are at a 1 to 8 ratio for 400 psi. So the question is, at what ratio do you mix your chemical when using different pressures. If you are like me and don't want to have to keep going out to the truck to change the pressure settings, you might prefer to just mix the chemicals to a different ratio for the pressure you want to work at.

I threw the ratios given to us on the hydroforce product manual into excel...

Hydroforce Metering at Different Pressures