Use case

When FormFieldState has autoValidate as true, it will validate upon build.
See: https://github.com/flutter/flutter/blob/master/packages/flutter/lib/src/widgets/form.dart#L419

This is a different behaviour than FormState when autoValidate is set to true where each individual field won't be validated upon build.
However, even when FormState's autoValidate is set to true, if a FormField has autoValidate set to true, then that FormField will be validated upon build.

Proposal

Since this might be a breaking changes for people who depends on validation upon build, I suggest to add an option to opt out for validation upon build on FormFieldState.

However, if we are okay with breaking build, it would be better if we can standardise the behaviour between FormFieldState and FormState.