Thank you Roy, I didn't know. Closed tickets are off use from my experience.

Hi Robert.

Well, you have a different approach apparently.
To make the story short, please make the image frame visible when "only axis aligned", as it is in perspective view.

Since the frame is invisible in the perspective view and visible in the isometric view the function does not work consistently.
Since it's hiding the frame in the perspective view it should also hide it in the isometric view.
The name of the function is: "only axis aligned". This means visibility is limited to only axis aligned view.
Since the perspective view has the frame invisible that means it is the proper way the option works. Visibility of the image with it's frame is turned off.
If it works differently in isometric view then it's not doing what it's meant to.
This means we have a bug.

Actually it is a bug.
"only axis aligned" should work the same in both types of views, it should make the frame visible only in the axis aligned view.

Yes, you are right: turn off the frame visibility in both perspective and user orthographic view.

Hi Philipp.

Thank you :)
Looking forward to the fix.

Here you go, from Blender 2.93.6.

The result is not close enough, that's the point.
All the flat n-gon's display should be optimised, but we still get some n-gons with all or plenty edges visible.

Hi Omar.

Hi Omar.
Changing the wireframe settings in the viewport overlay does not affect all, just some edges.
Display all edges is off by default.

Editing the visibility of the Geometry: wireframe, does not solve the problem.

Found the way to share the files.

Hi Omar.

I suppose I should file new tickets for all the bugs I find regarding this particular case.

On the system I was testing it initially the tweak tool had exactly the description as stated above.
Now I'm testing it on another system: