> #1 Make EC2 Auto Scaling decisions faster

Fuck yeah. The autoscaler is almost certainly a distributed, fault tolerant, highly available system that is deployed across multiple availability zones. Presumably they trade consistency for other attributes so there's an intentional delay to avoid making constant flapping changes. There's also the metrics granularity to consider. Take SQS for example, another distributed system. Many of the useful queue metrics are averaged over time, which adds a delay on top of the metric gathering period. The result is that a scale-to-zero ASG that scales based on SQS queue depth takes about 3 minutes to produce an EC2 instance from a cold state. If you're lucky.