This is why I have little confidence that Tokamaks and similar will have much success.

Instead of trying to prevent the non-linear behaviour of plasma it should be utilized.

Look at (grossly underfinanced) attempts like focus fusion, where there is no attempt to confine the plasma, instead self-interacting nature of the plasma is used to focus high temperature regions to a small region where higher temperature fusion processes can occur.

Long time plasma confinement is a dead end.