The answer to more technical tracks isnt that hard.
Have Expert and Pro sections. Beginners, inters girls and cruisers can race the regular sections and experts and pros get to hit the expert section.
Pros get to hit the Pro section.
You could even make it so the expert and Pro section has its own inside berm so the line is much shorter than the regular section. This way for new Pros and experts there is a decision maker, ‘ dont think your ready to hit that section? take the longer route’.
I would use the dirt from the am sections to border up to the Pro/expert sections to use less dirt and help keep the sides up.
The sides of all jumps should have enough backside so riders going over dont run a high risk of injury. the fronts and backsides of all jumps should also have enough dirt to enable rolling for Novices without too much circling the drain, but enough lip to let top riders launch so they dont have to roll step ups etc.