I had a chat with Professor Whyte about this about 5 years ago when he was starting on this quest. The key insight that he emphasized to me (that I could understand!) was the need to deal with the engineering. He told me that compact magnets would facilitate construction and maintenance because simply they would need less space and energy to be physically manipulated. This, as I understood it, would allow for huge reductions in cost because buildings and components scale in cost massively as their size increases. Small magnets won't need a huge building, they won't need special vehicles to move them, they won't need cranes to install, they can be swapped in and out during maintenance, and the work can be planned and executed by small teams at low risk. Who really cares if a team of 5 working for a week have a 10% overrun - that's 2.5 person days. On the other hand a team of 500 working for a year -> 50 person years. Scale is the overhead that they are targetting.

>I have a couple of physics degrees, hot fusion is the energy of the future and it always will be. This is not a physics problem, this is an engineering problem and we are just not willing to invest enough money to solve the engineering.

You're spot on. Which makes no sense at all. Given the potential of commercial fusion, we should be (globally) spending at least several tens of billions per year on R&D.

Assuming the engineering issues are solved, those hundreds of billions would be chump change compared to the economic benefits of volume of cheap, clean power.

Commonwealth Fusion Systems is privately funded and aiming to demonstrate net energy gain in 4 years. It's not like the lumbering ITER project.