how to revert firmware from v1.6 or v1.61 to v1.55? or maybe reinstall the firmware from a fresh download? with v1.61 there is a noticeable pregnant pause shifting from screen to EVF use takes longer than 2 secs; had multiple camera-freeze requiring battery eject to work again, and more times coming back to operation with camera recording 0MB, non working jpeg files only instead of DNG+JPEG in settings. had to do a factory reset to enable proper camera operations.