Ron my friend, I am so proud of you for doing this. Trust me I know first hand how hard it is and how I felt when I had to make that phone call to a vendor that I bought from.
What I have learned from my own personal experience is that quarantine with all new purchases and especially boids for a minimum of six months. Never share feeding tubs, never feed an uneaten rat to another snake, sterilize all caging, feeding tubs, and water bowls during the cleaning and feeding process. If mites show up, eradicate them immediately and follow up in two weeks from the date of the first treatment.
I learned this the hard way, however, I will never be sorry for the experience because I am willing to share my story and hopefully save other from my own mistakes. although I went through the live liver biopsies and only had 3 come back positive, I had every snake and cage destroyed.
Denial is a very powerful mind set when faced with this disease, my personal experience was possibly a little more strict than what others may have done, but in the end, integrity and ethics out weighed my own personal loss.