[Feature Request | GameLift] Ability to Invoke AWS Lambda Function On FlexMatch Events

First of all, I think the FlexMatch has amazing Architecture and Feature Sets by providing parameters When Starting a Matchmaking Request and extensive Matchmaking Rule Set Customization While matchmaking. But I think it Would be great to Allow more Computation possibilities when a Match is Completed, Timedout and etc.

I Understand that we can Setup AWS SNS to Invoke an AWS Lambda Function On FlexMatch Events.
But the Feature Request is about being able to Invoke an AWS Lambda Function Before Placing a Game Session in the Queue With the Ability to Read the Flex Match Data and Update the Game Properties.

This would make it possible to perform a final Validation and Processing before Placing the Game Session. One of the Many possibilities would be when a Match is Found Invoke an AWS Lambda function then based the Matched Players and Game Mode, Perform a Random Map Selection from a Pool of Maps and Set it in the Custom Game Property of the Match. Once the Session is Placed and the Game session is accepted, the Server already has the selected map in the Session Property.