Bear with me.

I currently use omnifocus for managing most of my todos, but I also flag incoming emails that need attention by setting the flag in Apple Mail. I then have a Smart Folder for flagged items that I return to periodically to clear down. Apple Mail flagged items also appear in the 'starred' folder on the underlying gmail account.

This works pretty well, but actually means I am maintaining 2 parallel todo lists.

Omnifocus will let me turn emails into actions based on To: or Subject: filters, but nothing else.

So my question is,

Is there a rule I can apply or a macro I can run that will add a string to the subject based on a mail's flagged status?

Then I can flag away, and have Omnifocus pick up the Actions.

Happy to use a mail plugin or something clever on the gmail side