PDH for a guy who is not 'a code expert, nor an electrician', you do pretty good.
I have actually in the past suggested (and was shot down) your idea of driving the circuit high. In my case we where asked to supply 24 volt camera power from a central point. The customer was quickly convinced to go to local power supplies.
However I think overdriving a circuit would be a violation.
110.4 Voltages.
Throughout this Code, the voltage considered shall be that at which the circuit operates. The voltage rating of electrical equipment shall not be less than the nominal voltage of a circuit to which it is connected.
It is also a questionable design as the load is not fixed, as lamps burn out the voltage will rise.
Call me conservative but site lighting has a long history and in my opinion re-inventing the wheel is not the best way to go.
I deal with site lights all the time.
The most common ways to deal with voltage drop are to use the highest voltage
available and increase conductor size.
Many commercial buildings use 120 volt bollards around the perimeter, it is not uncommon for these circuits to be very long.
We don't place transformers at each one we just use larger conductors with 3 phase multiwire circuits and try to feed the middle.
Costs, complexity and reliability are key factors in the design.
IMO site lighting should be kept as simple and basic as possible.
JMO, Bob