Is there a way in Lightroom to force update (read) metadata of image-files according to a list consisting of full-paths/filenames only?
That list contains the full paths to the files to be updated, the metadata has already been applied to the files that are in that list. The tool used is Exiftool.
Unfortunately Lightroom does not reflect those changes in a Smart-Collection. This behavior is correct as Exiftool was instructed to keep dates unchanged by using the -P option (=Preserve the filesystem modification date/time).