You might try something like the following in a tagging script. WARNING: Untested code follows:
$setmulti(_my_tags,album; albumartist; artist; title; tracknumber; totaltracks; discnumber; totaldiscs; date)
If this works as intended, it will set the value of each of the tags to
“not set” 0 if the tag is empty or missing.
EDIT: Changed the default value from “not set” to “0” because some tags (such as
totaltracks) might be expecting a numeric entry only.