Thanks for using the Bitnami Airflow chart.
Yes, Airflow can be extended with custom plugins. However, I think right now there is no easy way to deploy the Bitnami chart with a list of plugin. I wonder if that would be useful for your use case. Right now, the options might be editing the current chart to mount a custom volume with the plugins or create a custom docker image with the plugins already shipped in the image.
About this, I would say the worker will need them but not sure if the scheduler too.