Yes. He needs a skin cancer check and he can ask about treatments (although many derms won't discuss anything other than the skin check).
I've been doing IPL on my face and neck and it's working.
Tried it on a small spot on my arm and it didn't work there. Dr said it would not work there but did a test area probably to prove it to me.

You need to do IPL or other treatments very soon. Once it's close to summer many doctors won't do it because sun exposure is really bad right after these treatments.

Most offer both med and cosmetic options in the same office. He should definitely have a full body skin check first (can talk laser with doc too but book skin check first) and it sounds like you haven't had one either. It is very important for your health.

This is for my husband, who lived on a tropical beach in his youth with no sun protection. He’s now middle aged with a ton of sun spots on his face and on his back.

I know there are cosmetic derms who offer laser treatment to get rid of such spots, but first I want to make sure none of them are cancerous. Should he make two appointments, one with a regular dermatologist then a laser treatment place, or can a cosmetic derm do a complete skin check, biopsies, and lasers?

Any recommendations for specific practices? Thank you.