Being able to pull questions from a pool of modules for a request form (or nesting other forms) would be a huge help in creating/updating custom forms.
Our company has 40+ spaces, one for each department and collaborative effort. Currently, the only way for a form to place a project/task in the correct space is by creating a dropdown with each of those spaces as an option. If a new space is added, the new option has to be added into the dropdown on every form.
If it was possible to create one question as a module or separate form that could be nested into a new form, the question would only need to be updated in one location.
In addition to assigning spaces, this kind of option could be related to users, owners, folder locations and adding tasks. IMHO, modules and/or nesting could hugely impact the usefulness of request forms.