Squeak: What “death threats” written by the Rashba do you refer to?
(Also, what’s the non-far right in your estimation?)
Anyway, you didn’t get HaLeivi’s point – a gadol‘s own handwriting is referred to as “ksav kodesh”, but that does NOT imply intention to include it in the “Kisvei Kodesh” – the Tanach. Hebrew, of course, has no capital letters…