This works great if your print some certain parts and use FB for the rest. I don't remember the Thingverse number and could find the link later to the youtube, but there is a designer that developed parts such as connectors to bring edges of FB together and hinges for the door and parts for the wing, etc... 3d printed parts were for the complicated parts but the C130 was mostly FB. This is where 3d printing owns the hobby.
Fully printed parts strong enough to be super structure just skinned with FB are way to heavy to be efficient. Unless you over power the aircraft but then it flys way to fast and either has a catastrophic event or turns too hard that it again falls apart or crashes or isn't fun to fly. Why fly a cargo-ish plane so fast its hard to follow or enjoy?
I have purchased and printed the 3dLabPrint airplane files for the F4U and the B25j. In the end they were pretty and expensive and ugly. To get the printers such as Ender 3 pro (stock and heavily modified) and the Ender 10 (stock and a homebuilt clone) to be able to print the parts good enough, pretty much requires you to also purchase the slicer they developed it around. It takes many prints to get good enough parts and by the time you get it assembled and ready to fly, you might as well have just bought one off of the shelf for half the cost.
Think of the F35 program. It sells like a great idea, but the first few off of the print bed will have significant cost overruns.
How do they fly? The first few will fly like trash, crash, and get thrown away. It takes a few flights and a few prints to get it just right before it becomes fun and good.
This isn't great and just validates that mostly 3d Printed planes are not yet, 'the goto thing' at this time, its unique and interesting, but still needs tons of development and a proper plastic that is.... 1. Strong 2. a little flexible 3. heat tolerant 4. low density weight and 5. low cost.
Ease of printing like PLA, heat tolerant like ABS or Nylon, Low shatter on impact like PET. That kind of plastic doesn't exists, so far, the best I found is PLA + or PLA Pro. (same things) Labprints Pla air or whatever they call it seems like just regular PLA Pro from Overture. (of which overture pla pro is my favorite) The PLA Air, now that it's costs were reduced to 29 bucks a Kilo isn't bad. before when it was almost $40 per roll was rediculous.
I think the best way for this to work with 3d --currently-- is to print your airfoil parts but use them sparingly... just enough to help hold the shape of the foam board.
print thin pla parts for holding the shape of the cowl and engine as well as for holding the shape of the fuselage but used as the points where the edges of the different foam parts come together. This helps hold the shape AND is a backing to make the edges line up seamlessly.
Lastly, the 3d printed parts for controls like ailerons, rudders, elevators and especially flaps are extremely handy as long as used as the hinges and connection points as well as control horns.
This way you can have awesome designs that are a little easier to build with FB.
I think STATINE (op) has a great idea, it just needs to be a smart blend of printed parts with mostly very light Foam for the bulk of the air craft.
Don't get me wrong, I will continue to work with 3d printed craft (best used for boats) and I very much so love my labprint aircraft, they are just flying bricks that end up costing way more than the 60 bucks for the files and a few rolls of plastic.
Should you want to try, let me know and I will give you one of the more complex parts. Only the Stl they provide. 1 part --> NOT THE WHOLE AIRCRAFT.... the test part they share is not a fair part to test with.
There are complex parts on each of them and IF you can print those parts without critical errors and within designed weight +/- 3%, then you might have a chance at success, if not, then don't waste your money.