Well after what some have said about other supposedly 32GB limited devices working OK and finding an inexpensive 64GB card class 10 at 32GB price decided to give it a try.
Well its does seem to work OK in both the tablet and KB slots.
Correction.... it seemed to work but at least the Stock ASUS JB4.1 has difficulty with exFAT sometimes works but often doesn't. The only other format choice is NTFS which it doesn't like either.... seems 64GB can't be formatted to FAT32
So guess its back to 32GB and use the 64 for camera or something else
At least it was cheap not $50