Thank you for being flexible :-)
Headless literally means "gui-less" (without a gui) and has had the same meaning since 1998 or so so it's probably not a good idea to reuse the word to mean something else in the same context.
I would go with either "style-less" (which is a bit awkward to say") or "effortless", which is better even if not totally accurate.
With "effortless" you fully capture how easy it is to use.
> With web artisans I wanted to point out it’s for people who really care about every detail.
You can keep artisan - it looks correct in this context.