ASG instance refresh spends too much time evaluating instance health

I have an Auto Scaling Group using Lifecycle Hooks; the ASG is hooked up to an Elastic Load Balancer as well. When I perform an instance refresh on the ASG, the instances complete their launching lifecycle action relatively quickly and enters the InService state. However, the instance refresh then pauses for about 90 seconds after each instance enters the InService state, and the instance refresh status reason reads as following:

Waiting for remaining instances to be available. For example: i-XXXXXXXXXXXX has insufficient data to evaluate its health with Elastic Load Balancing.

Both the health check grace period and instance warmup are set to zero, and the associated target group is configured to consider instances healthy after 2 successful health checks with a 10-second interval. Given that, I'd expect to spend at most 20 seconds waiting for ELB health data, not the nearly 90 seconds I observe in practice. How can I configure my ASG to proceed with the next instance replacement immediately after the previously-replaced instance enters the InService state?