I don't recall having seen this particular question before, but I’ll give you my 2 cents: use the 1099-Q and move on. I’m not an expert on Coverdell. There shouldn’t be any additional penalty except the 10%.
I’m surprised that the plan administrator didn’t automatically distribute the money in the year you turned 30. The one wrinkle may be that the tax was due back then and you technically need to file an amended return. But if it was me, I’d just use the 1099-Q this year. You may want to contact the plan administrator for advice.
