I would love to have a vacuum forming machine.
I have a very long time friend who owns a commercial plastics shop and designed all his own machines.
They are not all that complex, the tricks being in designing a mechanism to rapidly lower a heated sheet of material over a mold (or raise a mold into the sheet) and then having a generous vacuum reservoir and large capacity dump valve.
All of that type of thing is entirely do-able in a home machine.
I will not divulge his machinery secrets obviously, but I can virtually guarantee that you have seen things his company made.
Hey, could that be a new FT product?
In a more hobbyist-friendly size of course.
Virtually all the necessary parts are already used in one 3D printer design or another.