Random but i always had a theory that reforming for a tailed beast was extremely painful i know there pratically full chakra but they do have flesh and bone i imagine that slowly reforming your entire body with no skin or fur would be rather painful it would also explain why kurama doesn't just let naruto die you could argue that the 8 trigrams seal forcibly lets naruto draw on kuramas chakra this isn't always the case kurama is explicity shown helping naruto like with summoning gamabunta you could argue that reforming just takes a really really long time thats not the best explanation since the three tails reformed in just a couple of years and even if it was longer for kurama i wouldn't imagine non existence is painful
But kurama is pure chakra ripping apart then slowly reforming entirely conscious throughout the process no body just pure conscious floating throughout the world waiting to reform would be pretty agnozing i think