Good Morning Greg,
Situ Drogon Rinchen, who is considered the 'First' Situpa was entrusted with the 1st Karmapa's prediction of his rebirth. The title 'Tai Situpa' was first bestowed officially on Chokyi Gyaltsen.
In reality, the Karmapa is supposed to be 'self proclaimed' .....prediction letters etc. so whichever Regent recognises is only acting on the previous Karmapa's indications.
I understand your points, I really do, and like you
I am quite happy to make all my points, then put disclaimer at the end saying that it really doesn't matter what I think
much love and best wishes,