Here´s a first hint: 33% or 40% as an average of upper and lower layer. I remember some dev has used those 2 numbers and couldn´t remember which one. And since my grass is still lying and drying with the baler parked next to it, I can only give u that. I´ll save when at 40% and try it. Whoever is first, posts here
Or maybe someone "in the know" can provide a solution before.