I too have considered setting up a dual height system. I know some older VWBug owners used to re-index the torsion axles when they got turned into dune buggies. The axle was an oval shape that allowed a different ride height depending how you turned it.
I have'nt had my tires
off to get a good look at the Boler
setup, but I think it's similar to this:
If I could remove the torsion arm from the axle and rotate it 90º and remount it, it looks like it would work. If it could be re-indexed without re-welding things, it could make switching the height back and forth possible.(The torsion arm would need to be secured with some kind of fastener instead of welding) It should work, provided it doesnt effect the alignment and tire wear too much at different ride heights, as you mentioned.Of course this is just theory at this point. Failing that I may have to go to lift blocks like Hans did here: