This really touches my heart. I lost a parent to leukemia, but the issue of blood vs. no blood wasn't a real factor (the strain had a 3% recovery rate in the age group and by the time diagnoses was made, there was no treatments available. Blood would have just prolonged things for a bit but there was no saving).
The HLC were there in the beginning when it was clear there was a major red blood cell deficit and there would be a lot of pressure for blood. But once we had a diagnosis, they pretty much went away and we were left to let our loved one die (a tortured painful death but at least we didn't have the vultures hanging around).
I'm so sorry you're going through this. These are terrible times you are dealing with and I'm sending you strength and healing thoughts.