Hi Joshua,
You mention you have read about ground level seeing, have you seen this article:
Altitude, Elevation and Seeing by Rene Racine
https://ui.adsabs.harvard.edu/abs/20....401R/abstract
In it the author develops a model to account for altitude of the site, and the elevation of the telescope to predict the seeing using data from 23 professional sites (including Siding Springs). His model agrees quite well with the data (~0.1" residuals)
A few years ago I entered the model into a spreadsheet with his best fit parameters, attached is the chart I made.
Notice most of the gain is the first 3 meters.The front of my telescope aperture is about 3m above the ground (in a dome) at 425m above sea-level near Arakaroola, and the best seeing I get is about what the chart says: ~1.1"
So according to model the 425m ASL doesn't do much, but the 3m does, I find this is not exactly what my experience tells me. My C11 or C14 at 2 meters elevation with the dew shield on in my backyard in Adelaide gets way worse seeing on average, although it can be very good (<1.5"), sometimes.
Note his model is possibly optimistic since he used only very good sites to fit the parameters. Sites in compromised areas (cities, rough topography, bad jetstream, etc) may not perform as well.
I think in my case being on a very steep ridge/hill, ~75m above the surrounding area (it's like a 75m tall pier?!?), does have a big impact as it gets the dome above the inversion layer that can form in the area. Compared to observing from the village itself, we know this can make a huge difference which I don't believe is captured in the model.
The problem I would see with higher elevation (very tall exposed pier) is wind shake. Even though you have a small sail area for your tower/pier, the vibrations induced by wind on a long thin member can be difficult, if not impossible to predict. So unfortunately you are entering uncharted territory with this design.
If you build the full height version (6-8m), can you cut it back down to 3-4m if it's too woobly? (I am presuming you have access to a crane to install the darn thing in the first place).
Best,
EB