That does sound more like a wart to me, too. My DS has had warts that sound just like that. I even showed them to his geneticist, and she did not even seem to be wondering if it could be a neurofibroma. If it were a possible one, she would definitely have been looking it over.
I'm going to throw something else out since I've been in the maybe it's NF1 boat. One thing I kind of figured out this year was that once you look out for certain things (especially if you have the full eye exam and an MRI), then a young kid with "possible NF1" gets pretty similar treatment to a kid dx'd with NF1 who hasn't had a glioma, brain tumor, seizures, troublesome plexi's, or bone problems. I used to looking for signs a lot, but my last appt. with his geneticist kind of set me at ease about not needing to do that. We'll still see the geneticist again, even though we don't even meet the cafe au lait criteria (his pedi. and I thought he had 6, but he doesn't) nor any others.
If he had one on his face or on the foot in a way that could interfere with walking, I would see the doctor for that, but we'd be more likely to consider treatment for warts in those areas, too, kwim?