The latest version of the stack, v4.3.1, introduces a new parameter: EnableExperimentalLambdaBasedAutoscaling. When set to true it will disable the default Amazon-AutoScaling-powered scaling behavior in favor of a Lambda that handles the scale-out.

The result is a much, much faster scale-out and a much simpler scale-in process that no longer requires lifecycled 🎉

For more information on this parameter, check out our Forum post about it: Experimental Lambda-based Scaler.