@a.twiddler is right about seats come in different sizes and styles on Bents like SMGTe and even SMGTs which being the old version in an old model was available in two or three seat sizes I believe. I have the larger seat size which suits up to 6'6" I think, one inch taller than me. However the bends in the glass fibre seat still have to fit you. If they don't then the idea that all Bents are like sitting in a comfortable chair is a myth. You still have to make it fit you just like DF bikes.
The SMGTe comes with a mesh seat on a metal frame. I suspect that's easier to achieve comfort. Also the GF seat on the SMGTe is a two part rigid seat that allows adjustability. However you cannot retro fit modern SMGTe seats to a SMGT AIUI due to different mounting points to the frame.
DF bikes get fit and comfort initially from buying the right sized frame, bents you usually have kind of one size. DF bikes you can fine tune seat, seatpost height, stem length, pedal crank length, etc. Bents you might have two lengths of boom or one length you might need to cut down if short, these are adjustable. Seat might be adjustable like SMGTe rigid two part seat or you adjust the angle as per your preference. You might change crank length, indeed I've heard shorter cranks than FF bikes are better. Bars can be changed to different types OSS, USS, tiller, hamster bars, etc. DF bikes you get flat, bar ends, butterfly, drops, and a few others. Along with adjustable stems.
Imho there's no excuse for not achieving comfort in any type of bike. Due to economies of scale I think DF bikes are easier and cheaper to get right. No idea how to sort my seat issues out. Might need someone to modify a seat from HPV to benefit from what I think are the better seats in SMGTe. I think there's aftermarket seat makers too but SMGT is an old model.