If you want to generate the "rest_file" you must use the MAIN, not the FS. But, if you want to patch a K770 CID53, you must first flash with :
K770_R8BE001_MAIN_GENERIC_VI_RED53
K770_R8BE001_FS_EUROPE_4_RED53 and customize with
HB1-06_Gen_CDA102864_13_R6A_GENERIC_EUROPE_4, because "executor" was made only for this firmware version.