Can butyrate thinner be used to thin nitrate dopes?

Yes, just as MEK and Acetone can be used. IIRC, Randolph aircraft dope thinner is same for both, but may be labeled differently.

MEK is a HOT thinner and so is Acetone, both which may require some Retarder to prevent blushing. In any case MEk, Acetone, and lacquer thinner from the home-stores are a lot less expensive for clean-up if one should want to save a $, but needs the marketed item for painting.

Good luck.