Even without LFTR, the new liquid metal/salt cooled reactors have a self-moderating design. (LMFR or LMFBR respectively) They could be modified to be multipass

Even without LFTR, the new liquid metal/salt cooled reactors have a self-moderating design. (LMFR or LMFBR respectively) They could be modified to be multipass reactors too, and already reduce waste a lot. The problem with multipass reactors is that fuel enrichment is the way to explosives... It took a long time to achieve safety with these liquid metal/salt cooled reactors, as Japanese can tell.