I stumbled on this post and see that you have attached new curves for several printers. When you say “1400 through P9000 printers” that would seem to include P400, but I think P400 is an “R2000 style printer,” so maybe it does not.
You also mention PiezoDN v2.6. I have never updated my PiezoDN since I installed PiezoDN-Windows almost a year ago. I never updated it because I was not aware that new versions were being created. Sorry I can’t tell you what version I have. There’s no manifest in the zip file.
The same issue exists for QuadToneRIP. I have never updated it since I installed in in early 2018 because I have no way of knowing if new versions are available. My version does not have a ppd file for the P400.
I am still hoping to see new curves for the QuadP400-PiezoDNP2 print model and a ppd file for the P400. Meanwhile, I continue to use the curves in the QuadR2000-PiezoDN-P2 print model.