Pagination events – include merge field?

I have tried to add a merge field into the Pagination Label settings on a form. I have a value in a hidden field that I want to add into the pagination value, but when I tried the merge field is not being merged at all.

Could this enhancement be developed into the plugin? So that we can insert a field name into the pagination values?

Specifically for my case, I am capturing the ad name that the user clicked before landing on the page (using the utm_content parameter) and I wanted to insert that into the pagination event, in order to see which ads are resulting in the best form progressions. However, the merge field doesn’t work. Any chance this could be developed? Or is there already a way to do this? Thanks.