Here's a reply I found by googling "Cozumel+Drone Rules":
Mexico requires drones to be registered.
sct.gob.mx/transporte-y-medicina-preventiva/…
Mexico forbids flying even registered drones over cultural or historical areas (so no flying over San Gervasio or any other
Mayan ruins, including the ones at
Punta Sur). Pilots have had their drones confiscated for flying over
Tulum, for example. Anything that gets too close to cruise ships (including boats, divers, or snorkelers) will trigger a significant response. The Faro Celerain lighthouse in the Punta Sur park would probably be considered to be in a historical area. I'm not sure about the lighthouse near the car ferry.
The primary NFZ (which is for both the civil airport and the military airport, so you're unlikely to have an exception request granted) covers most of
San Miguel. It ends about 100 meters north of Calle 23 Sur (so it covers the Catholic church on 20 Av) and extends to pretty far north (I haven't checked because my house is just to the south of the NFZ...).
The small civil airport Aerodromo Capitan Eduardo Toledo is very near
El Cedral, Money Bar, and Sky Reef, so you are supposed to have clearance from the tower before flying in that area. I have not tried flying there and have no idea how to get ahold of the "tower" for clearance or how responsive they are. There's usually an airshow there in March or April, and the skies are very busy during that. Last year it was held on the mainland, but this year, who knows.
The east side should be fine.
If you're bringing expensive consumer electronics into Mexico, strongly consider having a receipt with you so you can show it's "old". It's been the subject of debate whether drones fall under the duty exemption for photographic equipment - nothing says they do, nothing says they don't. Any DJI drone, and many others, will be significantly above the personal exemption amount and I know some people have been charged duty bringing a drone into Mexico.