I haven't been able to get the form to activate, am I missing a step? I've labeled my text fields and have the Customize Form option turned on in my design settings. So far as I know it should launch when the customize product button is clicked, but I just get the design.
After a bit of investigation I have come to the conclusion that it will only work when there is 1 page on design.
e.g - It works on a single sided business card design but won't work at all on a double sided design
I got it to work, I'm not sure what I did, just one time it worked and now it seems to. I am using it with a double-sided business card design, so it will work. My best advice is just keep trying!