I'm sorry about that! You're right...autosol does not pass place_waters=False correctly to phase_and_build and so refinement includes waters even if you set it to False. I have fixed this now and starting with tomorrow's nightly build it should work properly. Let me know if that doesn't do it!
In most circumstances adding waters in early stages of refinement is just a way to say "there is something here" rather than "this is a water" and so it should normally be fine to leave it as place_waters=True.
All the best,
Tom T