This will give you an idea of what you can achieve with Opus. This is the metadata panel I use to add and change metadata. It is, of course, bespoke and built to exactly what I require for my imaging needs. When you select a picture this panel pops up to allow editing or entry of metadata. It is totally compatible with Photoshop's metadata, thanks to the work the Opus guys have done over the last couple of years.
If it will be of any use to you I would be happy to post the VB code - which is quite comprehensively annotated - and you can bend it to your needs.