These PDF tax returns might look cool, but can cause a lot of headache.
The Dutch tax service experimented with them, a few years back. I could only do my personal income returns through one of these dynamic PDFs. The results:
1. All the different "pages" in the PDF were no actual pages, you had to navigate them using on-page scripted buttons and the PDF would dynamically overwrite a "page" into the content. Result: you couldn't PRINT the document! You would only get the first page! To workaround this, you could use a report generating button built into it, but its output did not match the screen layouts and it required data validation, so you couldn't easily copy inputs or send half-filled-in stuff to the accountant for review.
2. The PDF document seemed to append anything you did to itself. If you worked with it for a long time, it grew and grew. Even if you only corrected previous input it would grow in size. At some point Adobe Reader would take minutes on open or handle a keypress. I had to start over with my tax returns once, which was a pain because of (1).
3. When a new version of Adobe Reader came out, ALL THE OLD PDF'S WERE UNOPENABLE! Apparently, some scripting inside the document could not run anymore. All that was left was the static front page of the document. Very nice if you want to fill in a new return with your old stuff as a template. I wouldn't have cared to open this garbage if I could have printed it, but nooooo!
This stuff was the worst of the worst. And all while solving a non-problem. Arguably some of these issues were caused by a bad implementation, but some of them (the new Adobe not opening them) are fundamental. I never want to touch any scripted PDF again. Fortunately our tax service abandoned them next year. I cried tears of joy.