Ash HN: SaaS Pricing mode, PAYG or Fixed pricing plan

We launched https://formcan.com, a web form builder. Many people's first reaction is, oh, another form builder, reinventing the wheel. The truth is, we've been running https://platoforms.com, a SaaS product that converts PDFs to online forms, for 5 years, so rather than build FormCan from scratch, we got a lot of ideas while running PlatoForms and reused a lot of code when building FormCan. This is how we created FormCan.

One of the highlights is the pricing model, most form builder SaaS use a fixed pricing plan. We thought a 'pay as you go' model would make more sense for our customers, so FormCan will pay as you use it and the bill is based on usage. Prices range from $6 to $36, depending on the number of forms a user uses. However, I’ve received some feedback that this payment method is too complicated and that they prefer a fixed pricing plan. So my question is, what is the best pricing model for SaaS, PAGY or a fixed pricing plan? Would you accept PAGY for a form builder product?