I could understand not wanting this for rageblade, but as far as I see, Bloodletter really just provides about 50% more bleeding (60 something to 90 something? Was just a quick check. And essentially a level 2 Scim). Although I don't -need- Bloodletter, it would be nice to use it here and there because it exists and is usually unused, but the advantage of bleeding someone more but losing on Pith to help further drain mana or Eihwaz to hide an aff, etc, is not really worth it as far as I can tell.
TL;DR Let us empower or sketch empowerment runes on Bloodletter while we have it in our possession. Y/N?