Forms frameworks in AEM cloud

We are on AEM in the cloud and have a requirement to send a simple contact form that the user fills out to a backend email address. E.g. no emails being sent to users, no attachments, no data storage, just take the simple form POST request and send an email.

AEM has two frameworks out of the box, the older “Foundation Forms” Components and the new “Core Adaptive Forms”.

I understand the Foundations Forms are kind of deprecated and Adaptive ones are encouraged, and I understand the new framework has more features, etc.

but we already have implemented our custom designs (corporate styleguide) - but for Foundation Form elements only! (buttons etc.)

My main question is: can I still use Foundation Forms to send an email (e.g. by building a servlet or in another way), or is it not possible at all in the cloud?
If still possible but highly discouraged - what’s the Adobe roadmap for supporting such an approach?

Also: is there a way to send the email using an Edge service (e.g. not hitting AEM Publishers at all with a POST request)