I will definitely give Inkscape a try and I was able to get QCAD as well - idk if I randomly found them during server maintenance I tried getting it or what.
Doing an ‘on the road’ project yesterday I ran into the same issue again and I think that it clued me in to something; I suspect that when I experience this issue it is on curves that have used the contour tool in AD. When I have a single line I’ll want to extrude in S3D I use contour in AF to offset a clone a touch effectively giving the single line a width. The job I was working on yesterday I used this technique multiple times and the import was a mess but I think only on the contoured lines. The same with the wobble in what I poster earlier. That is a a circle in AF and I’m pretty sure I contoured it, connected at 1200 and 0900 and then trimmed the rest out. Not sure if that is relevant in helping solve the issue long term but I figured I’d share.
Also, which software is at fault here lol and why? If I can’t get good results with that extra middle step which end of my workflow do I need to consider changing?