Pre-Sales: Getting a sense of what's involved for users to edit forms

I've done a good bit of research and I understand that Gravity Forms does not allow out of the box users to edit their data later -- but I gather it is possible with some custom coding. What I'm curious to know is how much of an effort is that? Ie, if too much monkey wrenching is involved, and I would be trying to fit a square peg in a round hole, perhaps Gravity Forms is just not the right tool for this task.

Was hoping to hear from GF and/or folks who have personally dealt with allowing their users to edit/update past form entries. And whether any of the solutions involved the posting to Posts, or Custom Post Types or other methods...

Thanks much! Hoping GF is the right solution for me!