Custom Publication Types – WordPress – Complex Forms

We have on our website a very complex form that is generated with the help of Formidable Forms (Pro version). It uses a lot of conditional logic and is very heavy in terms of scripting as well as validation on the front-end. The added complexity is that after we submit the form, it inserts almost everything into a WooCommerce subscription.

The company wants me to redo the form as a custom implementation, that is, I remove the use of the Forms Form and customize the complexity, add a client and server side commit, move a lot to AJAX , and then refills the form if validation fails. In addition, save the data to a custom database table, then select the data and refill the form if necessary. Because many elements are based on JSON, the use of the back button in the navigation should also work.

Is it even a good idea? We would reinvent the wheel!

What are some of the challenges and complexities that I will face if we decide to go ahead with that? I'm pretty new to PHP and the initial research shows that it can get pretty complicated. Is there anything I can miss as a novice?

I am also after the right way to do that. Google search tells me that I should either create a template or create a plugin for that purpose.

Thanks for the reading.