That’s a solution that had not been suggested before. I wonder if the County would take them?
I’m pretty sure they don’t have a choice. They may resist accepting them if they are truly valueless since that is a net loss to the tax base.
But if they are undeveloped due to land use restrictions and city regulations, don’t be surprised if suddenly those restrictions evaporate and the city sells the lots to their crony developer du jour.
But owning property that has no value to you and produces no income is not an asset, it’s a liability. Gifting it for tax purposes is an excellent idea, far better than paying taxes in perpetuity in the vain hope that city government would buy a vowel, get a clue and change the rules in your favor.