It's strange, because almost all property tax systems in the US are based on ad valorem taxation.
I'm personally opposed to the concept as a matter of fundamental principle. Society can't function if people's property rights are constantly under the threat of being usurped by someone whose intended uses might generate more tax revenue for the state. People should have a right to use the property they own in the way that generates maximum value for them -- that's the point of property ownership. It's also why real-world ad valorem tax regimes usually include homestead exemptions or something similar.
Some of these LVT proposals amount to just turning the whole of society into a tax farm, and suppressing all variation and outlier use cases in the name of maximizing tax revenue. Georgism is fundamentally flawed in its precepts, and would result in a rent-seeking political state acting as a monopolist landlord.