Current Limitation:

The "Send message to Amazon SNS topic" action is restricted to a flat list of 10 key-value pairs. The "Custom" type only accepts individual smart values and rejects raw JSON objects with the error: "Invalid value. Enter a smart value."

Requested Change:

Add a "Custom Data" field to the SNS action (similar to the "Send Webhook" action) to allow users to define nested JSON structures and use smart values within them.

Use Case:

Users need to send specific nested schemas to AWS services (like Lambda or Step Functions) without the overhead of using an intermediate Webhook/API Gateway to reformat the