Calibrating Asus PA32UCDM for HDR

Hello,
I have been tying to calibrate my PA32UCDM for HDR and finally i got some decent results, i think it can still be better. its my 1st time trying HDR.

So i cam across a workflow where you do "1D post" gamma 2.2 pass before running a large cube for 1D+3D.
But i'm a bit confused and would appreciate some clarification.

So what i did is after Unity bypass upload to 1D+3D, i modified a DCI P3 D65 color space and made it gamma 2.2, i ran a Grey Ramp Large +, in the LUT generation i choose the newly modified DCI P3 D65 Gamma 2.2 as a destination and removed the check on Disable Gamut Mapping and created the LUT. Then uploaded that to the 1D post. Then ran a 17^3 cube using another modified ST2084 P3 D65 1000 nits. created a LUT from that using the ST2084 P3 D65 1000 nits as a destination, then uploaded that to the 1D + 3D slot.
I still have some issues with Delta E and RGB balance and also the EOTF aligning is not the best.

Any advices ? is my workflow good? am i missing something?
would appreciate any help!

Thanks

The 1D Post is a 1D LUT, so has no 'volumetric colour' component at all, as it is just grey scale.
So while doing a volumetric profile can help with the accuracy of the grey scale (although a 'large' Grey Ramp should be fine), doing things like enabling gamut mapping does nothing at all, other than slow down the LUT generation.
And using a DCI P3 D65 target colour space rather than any other target colour space that has a 2.2 EOTF is also irrelevant, as a 1D LUT knows nothing of gamut.
(However, it would likely be better to actually target the native gamut of the display, so the Colour Engine has to do less work on the gamut calibration, keeping the focus on the grey scale... this is explained in the various User Guides.)

With the final 3D LUT a 17^3 is likely not good enough, due to the excessive EOTF of PQ HDR.
You will likely need both a larger volume profile, as well as a larger grey axis patch count.
And you will also likely find that using Fit Space, Map Space, Or Hybrid LUT Generation options may produce better results.
You may even fine that using manual LUT Concatenation, as per that User Guide, helps.

Also note that using 1D+3D vs 3D only when uploading really does nothing to improve the final calibration, which should be obvious as the 1D+3D is being extracted from the single initial 3D LUT.
For users of Higher ColourSpace license levels with LUT Adjustment tools there can be benefit in doing the pre-1D and 3D separately.
(There can be benefit is using the pre-1D and post-1D to linearise the input/output from the 3D LUT, but that is a whole different level of calibration understanding.)

Steve