I don't love VTL, but in AppSync I used that generalized approach anyway (and rarely had more complex VTL templates for e.g. DynamoDB), so this is a great improvement: https://aws.amazon.com/blogs/mobile/appsync-direct-lambda/
Example from my code: https://github.com/ausgaben/aws-backend/blob/2ba3b6751a2eecf6b91b7e28f9e6a9a323d3bd33/aws/resources/GQLLambdaResolver.ts#L48-L66 https://twitter.com/BillFine/status/1291143280390860800