Tangential, but is that a conventional use of 'progressive?' I'm more familiar with seeing it used to describe the idea of having a tax rate that increases with higher, well, income most often.

I like the idea of smoothly ramping up taxes over time, in general. It seems to be the most obvious solution to the objection "this will shock the market," and that sort of thing. But due to the lack of a better term, I always want to call it "adiabatic taxation" (stealing the word from physics), but I think this is just a me thing.