Thanks!
It looks like the plugin author uses the tokens we've added to Jetpack's Contact Form module a little while ago. I'd suggest contacting the plugin author here, and suggest that they add tokens for other options, like the page permalink or the page title. That should help you.
I also created an issue here and we'll consider adding these new tokens to Jetpack itself.
Adding hidden fields in Jetpack would also work, but it would only be a work-around, and something that may render your forms less accessible for readers using screen readers.
Thanks for the feedback!