As I read the DJI Refresh information, my understanding is that they will assess your repair work and you either pay for it or get a replacement, your choice. My thinking is it is worth the $120 ($60 for policy, $60 for replacement) if a have a total crash or drop it in the water and recover it. All other repairs I would assess local repair vs. sending it in based on severity.
Many people think insurance is a waste. It really is just a form of spend some money so you have more options in the event of an issue. Like car insurance, sometimes a fender bender is better to pay cash versus submit a claim and have rates impacted.