@ Peer Just by hasard take a look at this niche program : White Rabbit CAD :)
It has some tools who maybe works for some figures! :)
https://www.tiesoli.com/whiterabbitcad/

You can send me some examples before / after wished for that i test with White Rabbit for the fun! :)
import 2D (pdf, svg) export SVG DXF
but Moi SVG, PDF --> Inkscape SVG --> White Rabbit

<< boolean union is that most lines get deleted, so maybe union only works for simple cases
Of course just boolean when "front faces" & lines are necessary...