I was thinking about it, and I think this technique would be really good for a fuselage for a smash drone or Bixler clone type of plane. I wanted to try this out as a replacement for hot wire cutting. I'm not sure how much 3" thick foam sheets are, but I know Dollar Tree Foam Board is cheap and it's easy for me to get. Plus, I don't know if I would use an entire sheet of the 3" stuff. DTFB would be easier to ensure that I don't buy more than I actually need, which would just be a waste. Anyways, I think it would be good to have a solid block of foam for the nose of a pusher trainer for rough landings and crashes.
I think a solid foam warbird would be good for the weight, warbirds are supposed to be heavy, but really great for combat. I don't fly combat, but a Bixler clone seems like a great idea. I'm not sure on the wings, but maybe a smaller 75% or 50% version might be sweet then I could just do a KF step airfoil.
I'm more excited about the prospect of a good pusher trainer than a warbird with this technique. I can just make up a design instead of trying to copy an existing one. It would be nice to be freewheeling the build and not trying to scale duplicate something.
I guess we'll see. But I thought I'd update my intentions with this. (I plan on using a spray glue to glue the foam sheets together. I'm not sure on the covering. I was going to say that I might not use any, but the foam would break off in a crash without some sort of covering.)
