They require testing or they are thinking about it? You can get a bike tested, and my understanding is it's not that expensive, but it probably doesn't make sense to use the test frame afterwards. The European tests lead to way overbuilt steel frames. It's unfortunate.
Since I decided not to go into the business, I will not build for anyone outside of my immediate family. And I haven't built for anyone other than myself. Too much stuff out of my control. Insurance is a big cost and doesn't make sense for me. That's a lot of money wasted for a few frames a year. I would rather not build the frames that would necessitate it. One guy in his garage probably isn't going to be protected by an LLC if a lawyer decides there is enough money at stake. It's obviously a single proprietor business masquerading as a corporation and lawyers will just laugh at the ruse.