The exfat option doesn't change the amount of fuses burned. Fuses only burn for major fw revisions, no relation to exfat support or not. You can safely "Update" to exfat support for the same FW version as you currently have with no efuse worry, autorcm or not. However if you ever use choidujour to update beyond your current fw, then you must always use autorcm or your fuses will get burned for the updated version, exfat or not.