Hello, a new "production release quality" of ExifTool is available. Version is 6.29. The version available in portage is 6.17 (the previous "production release" quality). 6.29 contains quite a lot of updates, better interpretation of EXIF flags (the rest you can see in the history.html, added as URL of this bug). I've extracted 6.29 in my local directory and it works without problems. Please add this version to portage. Thank you.
Version 6.36 (a newer production release) was added to portage. I'm am happy and declare this bug as FIXED. Thanks, Dan.