Yeah, wider sheets takes some work out of it. It's nice if I have the cash at the time to purchase the wider sheets, but even 4" sheets aren't that bad to work with.

One thing I do is make sure EVERY long edge where the sheets will be glued together is sanded on a LOOOOOOOONG sanding box. If the edged of the sheets aren't true when you tape or glue them together, it makes warps in the finished product.

Pics:
1st sheets will glue together along the seams and lie down flat on your wing.

I exaggerated the curved lines on the edges of the 2nd pic. These sheets might glue/tape together somewhat flat on the bench. But they will warp and bubble up on the foam cores.

Edge true all the sheets, with a long metal straight edge, or a long sanding block (4 or 5 feet long) before assembly. It makes a better finished product.