Excluding the Sufferer and Karkat, could any candy-red-blooded trolls have existed prior to SGRUB? or perhaps could they exist in a world like Hiveswap's? Also, if you have any knowledge on the matter, when does Hiveswap occur in canon? or is it its own separate canon?
Hiveswap occurs in the 90′s of B1 (john’s) Earth, I was to say 1994 more specifically but I’m not sure. And the Alternian portion happens a significantly long time before Hivebent. As for the candy bloods, it’s not entirely impossible that there were more.