The adapters have no noticeable impact on response or job time. They collect the queue time for each request or job in memory — a very simple operation — and an async reporter thread periodically posts those queue times to the Judoscale back-end. Check out the middleware code on GitHub if you’re interested.
Can I use other autoscalers with Judoscale?
You can use different autoscalers for different dynos. For example, you could use Heroku’s native autoscaling for web dynos and Judoscale for worker dynos.
Do not use multiple autoscalers on the same dynos, though. This results in very unpredictable scaling behavior.