as a matter of fact (fat?), the actual original source of that arbitrary limitation is indeed the windows Disk Format utility; over time, it just became assumed knowledge that, since that limitation was in place, that must be the maximum size that a given FAT32 volume could be, and so other utilities incorrectly followed suit. the actual maximum volume size is 16 terabytes.
the guy who wrote the Disk Format utility has spoken about this error a few times:
https://m.youtube.com/watch?v=bikbJPI-7Kg
https://twitter.com/davepl1968/statu...42158046146792
pretty interesting! in any event, replacing the sd card seems to be pretty involved. but if you really want to try it, go ahead and format your card as FAT32. the Kobo will probably be able to read it just fine.