Of course I know the answer, and so do you.
As someone who knows both how to use the chassis and how to use the jug, I can tell you absolutely the jug requires way less time and energy and provides a much more consistent result.
I'm LAZY!! I'm going to do things the easy way. At the race track it is mcuh Much MUCH easier to adjust a tire or a chemical than it is to adjust a chassis. Left side, not so much if you invested the time in your chassis during the week. But camber, you can knock yourself in a hurry if you don't take your time, make sure you've $1000s worth of equipment on hand and a couple good pit hands.
Air pressure is another variable. It's very dependent on the racetrack. If the racetrack stays smooth and together, you can run a ton of air pressure. But thats very rare in a dirt track. They tend to break up, chip out, develop ruts and holes. If you have tire full of air and you hit those ruts and holes, you don't have control of your kart. It's going to bounce, lift and land. If you have the tires flat then they will roll through the ruts and holes and you'll be faster.
There seems to be a misunderstanding between those who use the jug effectively and those who don't. We don't care for the chemicals either. But, it's the simplest, fastest way around the race track.
If you want to get rid of chemicals, you're barking up the wrong tree with tires and tire rules. You need to modifly the chassis rules. If you mandate an 1 1/8" frame rail, if you mandate a straight rear cross member, if you mandate a 16" rear seat height, if you mandate a maximum leftside weight (like NASCAR does), if you mandate narrow rims, you'll see the jugs go away. We use chemicals because it is faster to run the chassis free and the tire tight, than it is to run the chassis tight and the tire free.