With old school pen drafting, lines could be thickened to one side: a simple and wonderfully clear graphic technique, especially in sections. Only one programme that I know of has ever emulated this in 2D: the now defunct Micro GDS. If they could do this pre-2013, surely it can't be a difficult code to write? Would love to see it picked up in Archicad: any takers?
I grew up drafting with pencil and understand the quality of cad will never match on the fly decisions made by hand. A Big Part has been making better decisions on materials and their display. And that takes years to develop. Currently my drawings are closer to my hand drawings and more precise. It may be tricks you have to perform or showing a single width material in as part of your complex that has no value but to be seen in the drawing.
You can create a thickened line type that is offset but you need to trick AC.
Create a thicker line with multiple solid lines, then add a tiny offset line, no more than a dot. AC will read the tiny line, no more than a dot, and centre the line accordingly. But when you use it the dot is so small you can’t see it