I'm late to the party here, but I agree with leaving the matter of hemosynth to species' creators, with some leeway that the player can negotiate with the creator in terms of fluke genetics etc. I'm all in favour of scaling back things that are "100% effective" where we can from the setting, as having those exist removes the element of challenge and creativity of trying to find workarounds to things rather than using one-boot-fits all. It makes one wonder what Star Army Medical training is other than "apply hemosynth directly to wound, wait".