Dimensing To Layout Or Model Space Obejcts

In the gifs below, the dimensions reside in layout space. The green line is the corner of a Detail Window, and the pink lines are in Layout Space.
In the top gif below, the dimension is snapping to objects in model space, but the dimension units are using paper space.
In the lower gif, a new dimension is snapping to the model space objects, the behaviour desired here.
Can anyone tell me how to control this behaviour? I don’t know why the one dimension resists using model space scale units.

Hello - it looks to me like on the one using layout numbers you’ve used a snap (near) to the detail edge.

-Pascal

I am snapping to objects in model space (and layout space) in both gifs. Regardless, the first example stays in layout space units no matter how deeply into model space I snap. Perhaps it depends on where the first snap occurs; which, in the case of the persistently layout-residing dimension, I don’t recall.

But it’d be great to know how it’s supposed to work.

Is there any guidance available on this? I am again having layout-residing dimensions snapping to points in model space sometimes displaying model space units and sometimes paper space units. The behaviour seems random even with a single dimension style. I have to resort to copying dimensions that work properly when new ones do not.

As Pascal wrote, as long as you are only snapping to objects in a detail, you should be getting model space units. If you get it to snap to something on the layout, it will be in paper space units. If you have a simple model that reproducibly does something else, please post that 3dm file here.
-wim

Thanks for picking this up again. I realize this is the intent, but this is absolutely not the case for me on several projects. The above gif shows one. I recently uploaded a project to Dropbox and sent download priveleges to tech@McNeel.Com. That was for another issue but if you have access, please check it out. All my dimensioning is snapping to modelspace points, but about half the time I get layout space units and often give up on creating new dimensions and resort to the (much less efficient) workaround of copying and editing dimensions with correct units. Please take a look at this for me, it’s urgent. I will send download credentials to another address if necessary.