Agreed, using Marketo forms if possible is any day better than having to go through the hoops of background form submission from a non-Marketo form. The latter should only be preferred when the former is not an option. @Michael_Florin, here I believe @Romina doesn't want to create additional custom fields in Marketo to add on the Marketo form, so looking for options to be able to capture all the data with non-Marketo form and then pass the data to a single Marketo custom field in the coalesced form.
@Darshil_Shah1 , but in that case why use a AEM form. Why not just use a hand rolled HTML form, and some JS to manipulate the data into the hidden Marketo form and then submit it?
Yep, that's an option as well, @Jo_Pitts1! It's likely that OP and their team are using AEM as their CMS, so they thought of creating a form through it instead of a custom HTML <form>. 🙂