Howto edit XMP Metadata of multiple HEIC photos at once ?

[xnview-tom]

normally I am using my mac but HEIC metadataediting support is known to be done. Win10 should work.
So I tried my Win10 machine which has HEVC and HEIF installed, although not needed for XnViewMP
XnViewMP 1.6.4 fresh install, tried 1.63 as well

But multiple editing HEIC metadata as I am doing with jpeg not possible. Looking through forum issues I could not find a solution.

Metadata-> XMP edit is grayed out - cf. screenshot with HEIC photo being selected

Metadata-edit-grayed-out.PNG

- editing metadata of multiple jpeg files is possible
- editing metadata of a single HEIC file is possible
- heif.dll exist - comes with install
- heic write support confirmed

XnViewMP-HEIC-write-supported.PNG

- jpeg export to .heic is not possible - cf. screenshots
- jpeg batch convert to heic is possible

XnViewMP-HEIC-export-missing.PNG

What is recommended workflow to edit metadata of multiple HEIC files ?

Thanx for help

[xnview]

Currently embedded metadatas for HEIC is not possible

[xnview-tom]

thanx for clarification. will stick to JPEG workflow.