You definitely need to have a strong sense of code design though. The AIs are not up to writing clean code at project scale on their own, yet.
Not trying to denigrate the work here, as such. But this certainly didn't convince me that using AI to replace OpenSCAD (or any other major open-source project) is a good idea. The LLMs still aren't even close to being able to pull it off.
I mean, to be fair, a one-user project is not ever going to be as bugfree as a tens-of-thousands-of-users project. That's just inherent and not an AI issue. If you judge AI projects by that standard, they'll always come up short. It's a sampling issue. An AI project that's gotten to a level where it competes with a traditional project will always be buggier and less feature complete and polished, because AIs speed up development. It will simply have seen far less, well, polish to get there.