You asked, "Could a Hydrogen-Boron fusion reactor produce more power than it uses? Open Source Primer Fusion?"
——
I couldn't get yer reddit link to work, but I did watch the Primer Fusion video.
The concept is ingenious. The video is clever & well explained; professional work.
They're slightly too obsessed with the system being carbon-free & CO2-free [as byproducts], and as providing a solution to "climate change."
They're up to Rev. 2 of the system, using an array of neodemium [Nd] magnets inside each container hemisphere, to control the intensity & shape of the resulting plasma field.
Neodemium is almost as common as copper. An alloy of neodemium, iron, & boron ("NIB") can produce magnets far stronger than any other element or alloy.
Next step is experimenting with electromagnets instead, for more precise control.
Either way, it might be too expensive &/or too complicated for a residential heating unit.
Even if "cold" fusion can be demonstrated to work at small macro levels, it may not be scalable enough for commercial / industrial applications.
Worth tracking. Guess we will find out.
ThankQ for asking.
.