We don’t have that right now but we are considering it for down the road and appreciate your sharing your ideas.
We have seen members do two different things in the meantime.
1. Report listings – Use Ninja Forms to make a new form that is using the GD Contact Form template, but remove the email to listing owner action and just send to the site admin.
2. Suggest edit – Leave in the option to send to listing owner, but CC the site admin/editor-team with corrections.
In either case you can customize the form fields as you like.
These are simple to implement, and don’t come with the overhead of managing revisions or merging changes or a custom UI that needs to adapt to custom fields in each CPT. They are manual, but, they are possible now.