For this example, I'm using a form with the id of 6. I'm using checkboxes on page 1 (input_6_2) to reformat a multiple choice list on page 2 by hiding all the radio buttons, then showing only specific ones based on the values of the checkboxes.
This is just a bare proof of concept, you'll want to do some additional checks to ensure your users aren't passing impossible values (values from now hidden multiple choice selections). I found this solution to be more flexible than the PHP "solution" for a project I'm currently working on.
I hope these notes help others looking to implement something similar. Maybe the devs have a few comments about it.
P.S. I noticed some inconsistency in the identification and classification of inputs (using classes instead of ids in some cases) and I'm unsure as to why you guys don't use arrays for checkboxes and radio buttons. I was able to work around this but it wasn't without a little critical thinking.