Good to know but I wish I had known sooner. I've been formatting to exFAT for a while assuming that everything would be Mac/Windows compatible. In fact that's the only reason I have been formatting exFAT and now I find out it has to be formatted exFAT to a specific cluster size! I'm using Parallels to run Windows 7 to access my exFAT drive in Mac OS as a workaround because moving all my files off my 6TB drive so I can re-format to 1024 cluster size and move them all back again isn't feasible at the moment.
Does the same apply for LG TVs? I tried inserting an exFAT-formatted thumb drive into an LG TV's USB port and it wouldn't read it, so my conclusion at the time was that it was because they were only FAT32 compatible but now I wonder...