If empty value UID key exists in frontmatter, use this instead of creating a new UID key

[camfisk]

I would like to include an empty UID property in my templates, so I can pick where in the frontmatter it lives. Currently though, if I do this and then "copy URI for current file", an additional UID property will be created, rather than using the existing empty UID property.

Could we have it so that the existing empty UID property is used for this command, if it exists?