I am thinking about adding actions to a transactional email that asks a customer to fill in a review and currently links to a web-app where a complex questionnaire with several questions and text fields is available.
The amount of data that is collected is far more than would be achievable with the in app review action. However the registration guidelines state that the most high-fidelity action available should be used, but it doesn't really allow for granular enough data input for my use-case.
Should I use a Go-to action? Or is there a way to use the in-app review action to collect part of the data and then redirect to a partially filled questionnaire to offer the option to answer the other questions?
I think you should use the Go-To action. These are for more complex interactions, when you need to provide a direct link to the page where the action can be performed. They are rendered in an email as a button in the subject line that redirects the user to the page specified in the action definition.
https://developers.google.com/gmail/markup/reference/go-to-action