I've been on this KTM 350 for a couple of months now and I consistently struggle to keep the bike in a rut. It seems like the front end always wants to climb up and out of the rut. Sometimes I get it right and can hammer on the throttle, but most of the time not so.
I don't know if this is a setup issue or technique, but it's an issue I didn't really have on previous bikes. Suspension is all stock AER forks and shock. I changed the rear spring to get it right for my weight. Sag is at 100mm and I can't get it down to 105, seems I went just a touch too stiff on the spring. Forks are raised to the 2nd line.
That said, rear end 5mm high shouldn't cause it to climb up out of the ruts. I'd expect that to transfer more weight to the front wheel and keep it planted in the rut a little better.
I'm considering raising the forks a couple of mm in the clamps to see if that helps. Any other suggestions?