Brian H,
You don’t need break even at the fusion level with energy multiplication from the induced fission. Even with particle accelerators in conventional subcritical designs the multiplication factor is 60to1, to 60 times more energy comes out then put in, a D+D or D+T focus fusion driven reactor could possibly achieve even higher energy multiplying factors.
Subcritical reactor designs are usually very large, but replacing a giant particle accelerator with a much smaller focus fusion device helps.
The point is we have huge stockpiles of nuclear waste and not much we can do with it, but that could change if we achieve even limited D+D or D+T fusion using focus fusion.