Hello Rob,
I agree, it can be unfortunate that the Submit JavaScript doesn't support tokens.
What you may want to try is creating a custom Submit button and hiding the original Dynamic Forms submit button. This way you can embed JavaScript into the OnClick event of your custom Submit Button. Creating a custom Submit Button requires that you use the Question Type Text/HTML, and I know that tokens will render in this control so long as the Question has a lower sort order than the control you're referencing it from.
So try creating a custom Submit Button and let me know if this works for you:
http://www.datasprings.com/news/blo...mit-button This blog contains the techniques needed to accomplish what I mentioned above.
Please let me know if you have any questions.
Thanks,
Ryan