Do you mean, to change your mmcblk0p1 from vfat to some better FS? The 4G limitation is only for files on vfat, not filesystems. Or are you talking about a case where you have a loop-mounted filesystem on a file on your vfat partition, something like EasyDebian? In that case, yes, it's better to change the vfat to something else, like exfat or ext4fs.