Designer - is it possible to substract shapes w/o connecting curves?

[Sergiusz]

I have a few rectangles which I'd like to use to create a final shape, using substraction.

Red arrows point to the shapes to be used as substractors

 

What I got after substraction is this:

 

 

As you can see Designer connected final shape (red underlines).

The result I am after is this:

How I can achieve this w/o manually removing unnecessary curves?

Thanks,

S.

[Old Bruce]

You could think different and join the two Rectangles with the Add and then subtract that from a very large rectangle to use as a clipping mask.

[Cojo]

Create two rectangles.
The first rectangle in the desired size of your target.
Create the second rectangle by copying the first one and then resize it as desired, so that the edges get the later "width".
Then subtract the smaller rectangle from the larger rectangle. Only the edges remain. After that you can "punch" them out, i.e. subtract them again.