The lattice melting is probably not a major issue, you just have to cool it to remove the heat as it's generated. At a basic level you face the same problem in

The lattice melting is probably not a major issue, you just have to cool it to remove the heat as it's generated. At a basic level you face the same problem in a fission reactor and the solution is straightforward -- extract the heat into some sort of working fluid (or gas) to keep the fuel from melting. Fission reactor fuel is actually not even terribly dissimilar to the stuff described in the article, most often it's fabricated as a sintered powder. Again, this is super early so this is all wild speculation, but generally engineering challenges are easier to solve than fundamental science problems. Of which there remain a few. That said, most of the problems with MCF are engineering issues and we still don't have that working yet either so...