318 MAX fuel economy builds?

The problem with Rhoads is there are so many variables that affect their operation:
- spring tension. More spring, & they bleed down more
- rocker ratio. More ratio , they bleed down more
- oil viscosity. Thin oil they bleed down more, thicker oil they bleed down less.
I run them daily with a 213 adv dur at .050 cam. It's 23 degrees here. in 40 plus years running them I've had none of those issues. Oil matters but the time they have to drain is a bigger factor. What set up have you had these issues with?