This required a lot of support pillars.
So I decided to experiment with adding a 'pres-support' structure that sat underneath that section of the part, with a small gap to allow the built-in support to be added. As a test case I create a simple box, raised 25cm above the platform.
With standard Support:
With fractal hex columns
Cross section so you can see the fractal hex columns
I've not optimised this yet but even a rough attempt saves a LOT of filament.
I think this could be implemented as a fully automated support feature
Immediately under the part you have the interface layer, underneath that you would have a grid of hexagons small enough for the interface layer to sit on. The each lower slice you shrink the hexagons by 0.5x extrusion width and join the corners of the hexagons together. When the hexagons shrink to near zero size the lines joining them basically form a new larger hexagon and you continue the process with them until you hit the build plate
