You have just experienced the effects I saw in the other thread (internal connections ...)
with "how well the creating software saved the graphic or even in the DXF format"
wrote.

Individual elements of the DXF appear in the graphic as very short lines, but they are
originally very short sections of a circle with a large radius. Hence the huge ones
dashed circles in the QET element ...

I took the bother once and with Inkscape, my favorite drawing program
the DXF of the Sitop UPS 1600 is opened. There are front and side views as "symbols"
in front. I then copied the front view and pasted it into a new Inkscape instance.
Now the "symbol" was available as a regular drawing and could again be exported to DXF.

The QET element converted from this now contains almost 7000 individual elements, so
For example, the component cannot be colored because there is no closed contour,
there are no longer any huge circles for minimally short lines ...

My approach for a good QET symbol is this:
Import the DXF file into Inkscape and edit the graphic so that the number
Individual elements will be significantly lower to then use via DXF export from Inkscape
DXFtoQET to create a QET element.
Yes, that sounds awkward, but I find editing with Inkscape to be
more comfortable than with the element editor or other CAD programs. For the
The element editor is then of course indispensable for fine-tuning!

In the appendix you will find the Sitop UPS 1600 - DXF processed as follows:
- opened in Inkscape
- Front symbol copied (Ctrl + C) and pasted into new Inkscape window (Ctrl + V)
- Export to DXF
- an element created with DXFtoQET