The test here is a bit touchy.  We need something that actually produces a different effect when we change the gsparams.  In particular, we need the inferred FFT size with and without the gsparams change to cross a boundary in our "good" FFT sizes.  

Anyway, the change to how we calculate stepk in the presence of a shift (which happens all the time, really, with the 0.5 offsets for even-sized images) made it so the calculation in SBProfile ends up at the same NFT regardless of the gsparams.  So I changed the scale_radius to a value where the two numbers fall on opposite sides of one of our good FFT sizes, so they then round up to different final values.