I think it would be okay, but might not hold up well if you used it a lot. I took a closer look at how the phone fits in the current adapter. There is a tiny gap at the front of the phone, so I don't think it would bother a screen protector. It looks like the issue with the adapter is the back side of it has a slightly different shape than the Note 9. The phone initially goes in fine, but as you press it in, the back of the phone begins to press against the adapter. It's useable, but it would be better if Samsung would actually provide a replacement adapter for the N9.