Populating an XFA form from C#

Hi All

I've looked through some of the other posts but could find any exact info. I have some users who have a pdf template where they fill in a whole bunch of information. I was looking to do an application that would fill in most of the pdf form for users with name address etc and then the users would complete the rest of the details as they received additional information. They only have Adobe Reader DC (as do I at the moment). I downloaded the SDK and setup in C#. I'm wondering if I need the full Acrobat DC to be able to develop the application which is then used by users with Reader, or is there a way to do development work with just Reader installed?

Note: I've tried some 3rd party apps but it looks like once you fill in the form and save it, it is then no longer modifyable with Adobe Reader presumable due to the digital keys no longer being Adobe.

Any help would be greatly appreciated.

Cheers

Peter