Hello, Silvio,
if you're using the Assembly2 workbench you may use the "Mux" function to generate a single multi-body object that's able to be used in Techdraw and Drawing Dimensioning workbenchs.
To generate a parts list you may use Assembly2's 13rd function from left to right to export a table with parts listing to Drawing Dimesioning workbench. I'm not aware of any direct ways to use the Techdraw workbench this way for now.
Hello,
For my part, I use Inkscape software to add BOMs to my assemblies (and to add annotations, lines...). I find it is much more convenient than TechDraw.
Principle is to export drawing in PDF format and then open it with Inkscape to make the modifications. I make parts list with a spreadsheet software then I copy it.