Let me try and understand this in a more simplified way:
You absolutely do NOT have a need to unload or lift the inside rear tire. You have the need to free up or slip the inside rear, in fact if you can cause it to slip as needed it never even needs to leave the track. There is a big difference.
So I think, correct me if I’m wrong, Paul is stating that you can have a laydown seat, induce a fraction of amount of oversteer and slide the rear ever so slightly to unload the inside tire, and end up with slightly more grip from two rear tires rather than relying on just the outside tire to plant and use all of it’s grip. Therefore having more grip and being able to corner faster. Yes?
If this is indeed correct, I can tell you from experience that this might be somewhat of a valid theory on a slick track or on hard tires, but completely goes out the window when any form of grip goes down.
In club racing with hard tires and slick tracks, it’s pretty common (or at least this is what we did when we raced club stuff) to go for a slide oversteer condition to free the rear up and get the inside rear to slip, rather than trying to force the kart to lift and rotate. It was just much easier to get the kart to consistently oversteer slightly. And it worked, we were quick and won championships locally.
Slap on any other tire that is remotely softer and race on any track that has a bit more grip and it becomes next to impossible to apply that same theory. The kart actually has to work like it was designed at this point, and lift the inside rear and dig in on the outside rear and rotate.
I don’t think it’s possible to compare the tuning characteristics and theories of LTO racing with sprint racing. Every possible variable is different; tires, chassis design, seats, wheels, driving style, track style, grip levels… We never have a condition of “outside rear tight” as you’ve said. That doesn’t happen in sprint karting. If you’re lifting the inside rear, then your kart is turning. Do you have any experience with regional or national level sprint racing Paul?