As someone who has done Bozja a ton, now - like probably way more than most people - and who isn't collecting the notes (or going out of the way to collect them): yes, it's absolutely absurd. The mount isn't that special, and yet it is locked behind this multi-layered, hellish RNG, which itself is set within two of the worst zones in the game. There's no good reason for it to be this way, other than to artificially force players to loiter in Zadnor and the BSF hoping that certain FATEs and CEs spawn, long after these poor souls have completed every single other meaningful (or reasonable) goal therein. It's insanity, and it's frankly insulting.