I would say yes, also not too many stitches, and the correct support underneath. I have only stitched once on foam using a loose FSL design. It is fun!

Looks great when completed, but I do have to say my machine hated it. Yes you need to use the right designs.

I used puffy foam under the land areas, on a world globe design, to make them stand out and it turned out fabulously.
I digitised the design and the fill stitch I used was quite fancy and dense but I did not alter the stitch length though neither did I add any underlay. I had no problems stitching it out and I would definitely use it again.
Have fun!
Hugs n blessings, Meg

Dennis,
I have only used foam one time under a design. It turned out well, and at the time, I was not aware of designs specially digitized for foam. The design was fairly dense, of an antique corvette for my husbands shirt. He is a member of a classic car club. The foam slightly raised the corvette making it look nice on the fabric. I bought a few squares of different colors of the thin foam at Micheal's Crafts to match whichever color of thread I was going to use the foam under. That way if a bit of the foam doesn't cover, it is not so noticeable.
Angel

Embroidery library has a number of tutorials on several techniques including one on puff foam. Stitches flatten the foam so leaving out underlay when digitizing is essential to get good results. And using foam matching the thread colour is a wise thing to do.