I would like to request advice or support with
XnView MP Linux, Version 1.3.1 64bits (Oct 12 2022), Libformat version 7.126
on Linux Mint 20.3 Una 64-bit, MATE 1.26.0, Kernel Linux 5.4.0-132-generic x86_64
Have to admit, that I am not soooo deeply into Linux - more or less playing around on a secondary laptop. So please be patient with me.

I would like to use the included exiftool (v12.25) for modifying xmp-dc:subject and xmp-lr:hierarchicalsubject.
Under "tools-open with-configure program" I added "/opt/XnView/AddOn/exiftool" and then under parameters, added something like
"-overwrite_original -k -xmp-dc:subject<iptc:keywords".
When I try to use that on a photo with e.g. IPTC data in it, it should get copied to xmp-dc:subject, right?
But in my case, that does not lead to anything. Means, nothing happens.
Not sure, if this XnView-related or a Linux-related problem.

Any feedback would be appreciated. Thanks in advance.