If you broil a steak at 500 degrees for 9 minutes, you'll get a nice medium well steak. If you broil it at 500 degrees for 30 minutes, you'll get a charred mess. This is what has been shown by the e-liquid testing done so far. There are no magic settings. It requires a person, in a situation, using their senses to determine what is and is not acceptable. Luckily, it is incredibly apparent when a certain configuration is not working properly.
The problem with a standard is, it assumes uniformity.
Now imagine that researchers broil the steak at 500 for 30 minutes, then conclude that all cooked steaks produce charred messes, then trumpet their finding all over the media, convince the public that broiling steak is going to kill them, and then cry out that we need to regulate or ban all steak cooking devices as well as conduct even more testing on raw meat to gain FDA approval for broiling. Kind of reminds me of this vapor fiasco.