Yes it is. But since it's my first scratch build I went the "FT" way. Never built anything in foam at all. Bending foamboards with a heatgun is not in my plans, yet.
As I understand it, you shouldn't need a heat gun with 3 and 5 mm depron, at least not if you get the right stuff.
someone on a Norwegian forum once mentioned how he ordered a big stack of 3 and 5 mm from some supply shop, and they called him back and wondered how many model planes he was building
complex comes more in the form that you have more internal support and possibly other glues than hot glue, whihc owuld also help with weight, thoughyou can probably use hot glue as well.
personally I've ben sticking to ARF's or kits myself, thogh I at times want to try some of the ft planes, I end up deciding I can get a good ARF for the same price. and if I want to build I'd rather build somethign I can really put myself into, somethign balse that requires some work and time.