Seems like I am always chucking stuff by the threads so I decided to look at getting a six jaw chuck to hopefully cause less damage to threads. I ordered a cheap Chinese Sanou six jaw 6 inch chuck off Ebay. It arrived in 4 or 5 days and fit my machine without any modification to anything. The chuck was full of grinding dust and grit so I cleaned it thoroughly.

Shockingly, the thing seems to hold a thou and a half of run out through its' range. Maybe I got lucky.