"Some dump angle has been lost at the very top of the lift arm travel, a new design for the z link needs to be done too."
I have the same issue on my 990 . When scaling off the the sales brochure it's hard to get the right shape of the pivot bar .With my archaic cad program it's hard to simulate the movement .Good note to that is I got a new 1 made up that should fix it

. I'm surprised that with what they are brought up to be , they don't have the means to simulate before production or worked it out with the prototype

. I guess if no one complained no need to worry
would be nice to see that D9 south again this spring . hint hint