This 'Georgian' tax scheme looks good in many ways. More below, but first, your question:
I don't know about other zones, but I live in a town that highly values open space and natural environment. This is a town ~35 miles away from a major city (top 10/20 in US), with no rail or mass transportation, or substantial business.
This is not the same as residential towns/zones more adjacent to the city, and I'm not making any arguments about those.
But for this town, and several near it the residents do a LOT to deserve the increase in land value. 1) Everyone in the town pays, and has paid for decades, substantially higher taxes to maintain the open rural character of the town, which includes the town buying parcels of town to keep open. 2) Everyone in the town foregoes substantial development opportunities available for subdividing land. 3) Everyone in the town pays higher taxes for high-density developments that do not happen to preserve wetland, environment, or usable open space. 4) Everyone in the town pays extra costs maintaining habitat rather than clear-cutting. 5) Because of the lack of development, the values have gone up LESS than other such towns in the region.
Yet everyone yells that this sort of town should be subject to the exact same massive high-density developments of other towns, utterly destroying the environment and town character, and yet providing nothing of value. A new lower-income-accessible house in such towns provides ZERO advantage to a supposed resident, who would now become absolutely dependent on a car and all the required expenses, being located a multi-hour commute from jobs in the city and no public transportation. Meanwhile, entire habitats of endangered species would be destroyed along with the character of the town.
It should be a different call on locales closer to the city (although I cannot speak for them). Particularly in zones near public transport such as rail lines, where people can get to/from work without the expense of an automobile, higher density should be encouraged, so their income can go towards building wealth in a property.
The Georgian idea looks quite good to me, as long as it respects the value of land conserved for natural habitat and open space. Such land should be completel different from a vacant lot with a torn-down building or parking lot — the "rentable" value of habitat or open land should be zero, since it cannot be built upon.
That said, it also looks like this 'Georgian' tax scheme would likely eliminate all parking near the city center very rapidly, or make it very expensive. This change should not be left to unintended consequences. Either provisions for parking should be made (force tall high-quantity parking garages?) or better yet, provisions for reducing/eliminating cars in the city with extensive public transport, low-/no-tax for bicycle parking? Probably different for each locale, but it needs to be planned for.