Here what in the manual:
The Bars Widget provides another indication of the measured colour error, relative to the target colour space.

In its default mode, the bars show any colour error based on R, G, and B values, with the displayed error a combination of gamut and luminance, with the 4th bar showing luminance independently, and the 5th, chequered, bar show the dE error.

In addition to the height of the bars defining the colour error, the intensity of the bar's colour increases with a greater error value. The Bars Widget auto zooms resolution, depending on the measured error value.

I like that autozoom on colour errors, but what happens is that, depending of colour error, also dE bar is scaled. Autozoom values are 1, 2, 5 and 10. dE bar, with no zoom, is cut at 2.1, corresponding to the beginning of perceived colour error. As is also zoomed, it is cut at 2.1 (AutoZoom=1), 1.05 (AZ=2), 0.42 (AZ=5), 0.21 (AZ=10).
I appears me that in this way, the original intent of the dE bar (i.e. giving a visual indication of the perceived error during manual measures/measures inspecting) is lost.

Another point, maybe a bug:
It is said: In addition to the height of the bars defining the colour error, the intensity of the bar's colour increases with a greater error value.

Have a look to the attached snapshot:

Look also at the end, where you can see also the correct RGB level
I see the red bar less intense depending on the red colour error. I cannot tell if it is a manual error, or if it is intended, or If I am missing something

Sorry, no idea what you are actually asking for?
What is the issue with the dE bar?
It seems it is working exactly as expected...

With the RGB bars you say: "I see the red bar less intense depending on the red colour error. I cannot tell if it is a manual error, or if it is intended, or If I am missing something?"

But also quoted before that: "In addition to the height of the bars defining the colour error, the intensity of the bar's colour increases with a greater error value. The Bars Widget auto zooms resolution, depending on the measured error value."

It seems you answered your own question before you asked it...?
Or are you (incorrectly) assuming 'intense' means brighter, and less saturated?

Steve

Basically I would like to have the dE bar not zoomed.
If for colour bars it makes a lot of sense zooming (i.e. aiming for the best result and getting easier tweaking), for perceived error does not give any useful help, as, with zoom, it is too much often, 100% full. I know the manual does not say that and for this reason I tried the WIBNI way.

About the second part:
I understand (https://www.merriam-webster.com/dictionary/intense) that intense for colours is having or showing a characteristic in extreme degree. Yes, so luminance/saturation. Which different view do you have?
PS: honestly it is the first time I have noted that. During calibration what attracts my eyes the bar size. But I have found little bars more intense, and I have no problem with that, a part the manual, but that very minor.

I think I have clarified. Still unknown?