I commend anyone who undertakes the project to make a fusor. It is a great technical feat.
So far what I've seen in these projects is technical. Learning how to build and maintain vacuum systems, building and safely using high voltage supplies, managing instrumentation, running the device and collecting data on its operation to tweak and modify the operational parameters.
I also see that success depends on access to funding or "salvage" equipment. Even trying to build a single demonstration/experimental plasma apparatus for my classroom is running me several thousand dollars. Once I spend some time with students studying plasmas with that device, I'd love to try a fusor just for the fun of it and to develop some scientific questions that student's might investigate with the fusor. It isn't the technical ability of my students that limits our ability, it is the resources of time and money.
Still, the thing that has limited my interest in the fusor project is the lack of existing classroom or student project scientific applications. Not just building the device, but what experimental questions can we tackle with the running hardware? It is not enough, in the long run, to just build the apparatus. That achievement puts you at the starting point of scientific investigation, not the finish line.