Agreed on camber. To me, even the number isn’t important because most (all?) karts use discrete adjustments for camber. Who cares what the number is? Just find the hole that works.
But just using total toe doesn’t sit well with me. At the very least you will be wearing your tires unevenly. Also, as mentioned above, when you string a kart on the ground you can account for driver weight. I could see a combination of stringing and toe plates-Strings to set up toe evenly in the shop and then toe plates for tuning at the track. As long as you’re careful you should be able to keep your toe even side to side.