AWS Elastic Beanstalk Worker - Scale Based On Number Of Available Queue Messages

I'm currently using AWS' Elastic Beanstalk workers for a queue of mine, the metrics available to trigger the autoscaling are pretty generic (CPU, Net in, Net out, etc).

I'm curious to know if it is possible to use a trigger based on the status of the queue attached to the worker - specifically adding or removing instances based on the average number of available messages in the queue over the last X minutes?