I never normally evap my solvent.

Freeze precip and reuse a few times then I tend to mix it in with the fuel for my mower or hedgecutter.

Could clean it up by distilling but that seems like a waste of power (when I can use it as a source of energy instead).

One thing I have noticed is that if you supersaturate your naphtha on a fast pull is that a lot of the spice will crash out as it cools to ambient temp. You can then decant the naphtha off and freeze precipitate the rest.

Like the sound of the centrifuge wish I had one to play around with.

All the best with your experiments.