It seems to me the idea is sound but the specific implementation very difficult to get exactly right. Tax it too much and no one will want the land. But unless you tax it enough to really spur development it won't have an effect. Finding that sweet spot is the key, but is also going to be a moving target.
I think the specific implementation isn't that hard. The main idea is to provide an incentive to build by not taxing structure value. If you're taxing a territory that is currently half structure value and half land value you can set the land tax that replaces the property tax to double the current rates. Then your city revenue is unchanged. If plenty of land is blighted or empty then the average increased tax on land should be less than the tax of a reasonable structure (SFH for example). Townhouses and condos save by having less land per unit.
