no other way to put code only once and new update will automatically take effect and ticker too ?
as you told “”if there available the new update,you need to copy again the content of the header.php on the parent theme””. i never checked BTW what new updates came with. is there any place where you show that these are the new features/fixes has been added or any place where you tell these files’ code has been updated ? for convenience to check and to update in child themes etc ?