Z9+ Characterization and calibration using external spectrometer

[XetYr]

Dear community,

I'm a photographer and I'm using the HP Z9 24" since one year now. I want to improve my color pipeline, from screen to print.

They're is my problem :
I'm not satisfied by the embedded spectro, the calibration process is not customisable and the repeatability of the results is not satisfying. If you create 2 profiles using the same paper roll, the same cartridges and the same print-heads are producing 2 different prints.

As far as I know, I always calibrated printers using an external spectrometer and software, in order to set the number of patches, and master the profile created. I used to create charts with the i1Profiler software (now Calibrite ccSutio) and print them with the Adobe Color Printer Utility (ACPU), in order to bypass the color management from the printer.
Then, I digitalise charts with an I1 spectro and created my own profiles, loading them later on the printer.

Today, if I try to follow my practice, I'm not sure to be able to deactivate the color management on my Z9+. I'm stuck with the driver, which purpose to choices : color managed by the software or color managed by the printer.

How to be sure to print without any profile if I select "color managed by the software" (in this case, it's ACPU right ?)  ?
Indeed, when you load a paper in the printer, you are obliged to select a profile and I'm afraid to print with this one I selected when I load the paper.

I searched for months on Internet, forums, reviews etc... I found nowhere explanations about how to print without any color correction !
Nowhere except this guy who found a "hacked workflow" :

"Impossible to have a Postscript Acrobat PDF assigned no color correction. The only solution is to tag the charts with Prophoto working space synthetic profile. This is not the way it should be. I asked HP in the beginning about this yet they have not done anything. Considering the level of this printer it is an absolute requirement."

I'm agreeing, it's a requirement. Print without color correction is possible on 10+ years old printers, and easier than on this brand new Z9...

Can someone or HP help me to solve this issue ?
Thanks