Best practice for using GitLab runner autoscaling on AWS

I’m new to GitLab and just started using GitLab autoscaling runners to deploy IaC on AWS using this guide:

I see the recommendation is to use docker.machine drivers which have a parameter option of --amazonec2-zone=x to determine which AZ to use. This hard codes the specific AZ within a config file on the runner manager. I would really like to avoid setting a static parameter because AWS can have failures in specific AZs, however unlikely to have a failure across a region.

Is there a suggested solution to dynamically set this parameter for each runner call to provide some sort of load balancing, or better to detect if there is a failure in spinning up the EC2 runner and retry with a different AZ parameter?