and it therefore cannot reasonably be argued that the blood of such is sacred. -
According to the HS, blood is intrinsically sacred on its own to God and it’s sacredness does to depend on being used for animal sacrifices to atone for sins.
distinguishable from the consumption of blood
That is not the case because in the HS blood could not be used or stored because of its symbolic sacredness. Also, whether or not blood is digested in the stomach, the recipient of a BT consumes blood by using it inside his body and in time absorbing it. There is usage and benefit from the blood of another creature by the transfused.
The Christian injunction to “keep abstaining from blood” cannot be invalidated and does not grant permission to use blood for any reason. The tension is not whether or not the injunction means medical use or any use of blood but whether God allows violating it to save a life.