Mav said: “They do have a scriptural basis for abstaining from blood...”
You ask the impossible. You and all living JWs do not abstain from blood! It is surging through your arteries and veins as you read this. I doubt that you want to follow George Washington and have your blood removed from your body (phlebotomy).
The phrase (standing alone as JWs use it) “abstain from blood” is absurd!
I have seen all the works which have been done under the sun, and behold, all is vanity and striving after wind. What is crooked cannot be straightened and what is lacking cannot be counted. Solomon