It would be cool for changes made to metadata to be remembered on a metadata clipboard.
You could paste the change to other files.
Davinci Resolve has this. You can select a clip, Ctrl + C to copy, but instead of Ctrl + V to paste the clip you Alt + V and you get a dialogue box to choose what attributes of the copied clip you want to paste to this clip. It's like a style picker.
So a hotkey for 'paste most recent metadata' would be nice. Make a selection push the hotkey and all those files would conform to your last metadata changes. Without any dialogues or having to copy the source first.
(Also note that it's easier to do with the metadata dialog instead of the panel, unless you drag the other files out of a separate window to avoid the panel changing when you click things to drag them.)
This is effective but very slow if using the 'Edit Metadata' dialog in the Properties drop-down list.
after copying metadata from one file to another, one must re-open the 'Edit Metadata' dialog for each file.
Please consider adding arrows like there are at the top of the Metadata Pane so one can advance to the next file.