There should be other ways to obtain the Field notes.

[Driavna]

oh that's interesting rate,but unlike extreme though you get do to the fight again and not drop and re reque and again2 but you get totem for maybe wep or mount later day, but this amazing bojza fate mechanic make people went insane of waiting for 2hrs+ to do 10min fight to be dissapoint to not drop and has to wait again without any pity system to assure "yea you'll get it in 2-3 times" but nope, rng Inside of rng

I personally know players with a high amount of Ex Primals kills and no mount (I'm talking about 200+). And yes, totems can be exchange at a later date, however you have to wait months. Probably at some point SE will add a coin exchange for field notes.