Exactly. Infill would be 'bad' as it's a model of an aircraft that's supposed to fly when you've assembled it.
Still. What is this issue called? I'm not even sure what the term for it would be, and I'm thinking that it would help to know what to call it to look up solutions.

Also, as an attachment, 3dprintboard shouldn't care what the image size is, it should just take the file.
That didn't happen either.