This is solvable. If a trust owns the property, default to the highest tax rate. The trustee is then responsible for providing proof of the beneficial owner(s) if they want the "discount" rate.
This is basically how income tax law works for trusts. The highest tax bracket is reached very quickly to quash the first order shenanigans that might result from more preferential treatment
you skimmed over this part of his message:
> automatically charge this elevated rate for properties owned by non-natural persons