Yea. I am sorry that I must have kind of skipped the end part of your help request after seeing you were looking for a popup. I have been making heavy use of this functionality in my template usage lately and was excited to share it with you.
You could perhaps have a template with links instead of variables. And then try to use the functionality that creates a new notes with the matching names to the corresponding links. And then have the rename functionality let you rename each of these values thus updating the links to them in the initial note first generated. At that point you could just copy the note content while in Reading View and paste it into a new note and delete all the notes generated in order to make this work, so that everything is clear for next time.
It looks like you already understand this stuff more than me, but in the file module section of the Templater documentation these different functions I referenced in this workaround are described.
Good luck! Sorry if I wasted your time. Thanks.