Thank you for your fast answer.

In my opinion you can do this only in circuit diagrams. There is no relationship between the size of two diffrent elements.
If you create a assembly plan this isn't usable. In assembly plan the scaling for each element should be the same. Otherwise the assembly plan is more a good draft then a exact plan. 

Is there planned an improvement for handling assembly plans in the near future?

Hallo @ all,

I have a little problem, when I use dxftoqet-converted elements in qelectrotech:

I create a symbol by LibreCad as dxf file. Then I convert this file by DXFtoQET.exe. If I used this converted element in a diagramm, it is displayed very small.(scale factor is about 0.3)
If I compared the values in the elmt-file with the values in the dxf-file, i couldn't find any fault.
May there is a problem how qelectrotech does interprete values of x-, y-coordinate, height, width, length,... in the elmt file. 

I attached the elmt and the dxf file.
(used qelectrotech version: 0.6)

Thanks