I had a pretty complex custom form with about 50+ fields on it. There's a lot of JavaScript and jquery on the form, plus some tricky validation. For me there really wasn't an option to use an asset builder.
Then I needed to build a members dashboard where the form submission can be searched, listed, sorted, counted, and some data edited. As far as I know, the submissions couldn't be searched, so I had to find a way of making the submissions searchable. That's when I read the squiz manual section about DB assets. DB assets are essentially blank pages with metadata applied; so I thought why not just apply the metadata to the submission? same thing.
I found out that I only needed to search, display, and edit about 12 of the field values, so I created a metadata schema and applied it to the submissions folder, then I have a trigger for each of the fields I needed, which populates the metadata on form submit.
Such an easy solution to a very complex requirement.
On hindsight I'd love to do this using JS API, but Squiz tutorials are pretty none existent, and the manuals are often very vague at best. Plus stuff like SOAP, REST, JS API's, and all the other goodies that would really help, are not covered in any of their training. Maybe there's a case for someone who knows this stuff to set up an independent training consultancy focused on getting the best out of Squiz.