That’s not a 4% return, that’s a 19% return.
.4% here, 19% there, pretty soon we’re talking real repeatable results.
It does recall the first laser. It was in a huge room with tons of equipment and a monstrous power supply. When the engineers got into it they eventually developed the handheld "cat chaser" that we have so much fun with.
Here's a good article about the breakthrough.