One thing I thought was a big change in the WTS blood doctrine was the approval (by individual conscience) of the hemoglobin-based products.
Products being developed from human or animal hemoglobin could be used to treat patients with acute anemia or massive blood loss. KM 1/06 p.5 "Products being developed from human or animal hemoglobin could be used to treat patients with acute anemia or massive blood loss." Quote from https://www.ajwrb.org/watchtower-approves-hemopure
For Jehovah’s Witnesses who are evaluating these issues we would simply point out the kind of tortured logic the WTS is employing by taking the largest single component of blood from an animal (hemoglobin) and saying that a Christian may use it in good conscience while at the same time arguing that a tiny component of human blood like platelets are not permitted. This is certainly not something that can be substantiated with the Bible or even science for that matter. We believe the only reasonable position is to allow individual Jehovah’s Witnesses a free choice in their medical treatment." That link to ajwrb.com is an ex-jw site with good info on the WTS blood doctrine.