Just checked in PL9.2 … and with workspace Standard it looks like this
Not that I understand the given explanation
“The observed behavior is intentional. The first Denoising & Demosaicing section is for RAW images. the second is for RGB images and the third is for non calibrated RGB images.”
???
So there’s 3 different denoising engines potentially at work depending on your file type (I’m sure you knew that much) but… DxO can’t have the application intelligently show only the one most relevant to the file type you have loaded.
(They also apparently can’t amalgamate the different controls into one panel and grey out (or even better, not show) the options not suited to your file type)…
As a developer, the first thing I would do when writing this code would be to title the 3 sections according to the design :
Denoising & Demosaicing (RAW)
Denoising & Demosaicing (RGB)
Denoising & Demosaicing (RGB non calibré)
This would be the bare minimum. But there’s more to it. All sections are coupled for the Chominance and Luminance parameters (why ?) and the available settings obviously depend on the image currently selected when opening the editor. Nonsense.
What I don’t understand is that I had this problem of 3 identical palettes a few months ago but since then I have only the Denoising module once.
And I don’t know why that changed but I’m not complaining.
Well, I had opened a raw file and the second option was “active” (= showing settings), which doesn’t make sense (to me) … while referring to DxO’s explanation it should have been the first one.
However, I don’t care and honestly I’ve never noticed all this before, maybe as I rarely use custom presets. 
Just to be sure : Is it clear for you that the 3 palettes appear only when the preset editor is opened ?
Seems a bit of a re-occuring theme when it comes to the UI/UX.
While I don’t think any of this is show stopping when it comes to using DxO, I do think it makes the process needlessly complex and “busy” (two separate issues).
I’ve heard it said that Adobe purposefully dumbed down e.g. Lightroom but… it surely holds the dominant market share and is a favourite of both novices and professionals alike. I don’t think that’s all down to the UX/UI, but it works.
Nevermind some of the functionality LR possess that DxO really ought to - to the point it’s a no brainer - like numerical values for HSL sliders, mid-tone colour grading, and RGB primary calibration.
Neither did I until I started to work on a mix of photos coming from various APNs, Fuji X-Trans and non X-Trans. Custom presets can help in that case.
Agreed. And I think I know why. At this level of complexity, UIs have to be designed as Finite State Machines. This is the only way of keeping an UI consistent and stable. By observing the behavior of the Photolab UI, I’m pretty sure that it’s not the case for this software.
Now yes, a few months ago I had these 3 identical palettes all the time.
Just spent an interesting 10 minutes learning the very basics of Finite State Machines to try and understand that one but… yes, I couldn’t build one but I understand enough to say I agree!
Ah, now I see what you’re talking about! Yes, Denoising & Demosaicing is listed three times when I edit my custom default preset.
After several updates, I’m still unable to understand how the Details section of the Photolab preset editor is working.
Any progress anyone ?
I had completely forgotten about DxO’s “explanation” and couldn’t figure out what it is
… until I opened the preset editor and, still confused, tapped the ?-help on the right.
Thanks for bringing this to our attention - - I had noticed that point in Release Notes, but I had not related it to this issue.
It’s encouraging too - as it suggests that DxO does monitor the forum … 
