Currently it is very low level to override the default behaviour on how many threads are assigned to the publisher/consumer.

We are seeing too many GAX threads created for our usecase causing an overhead in memory consumption on k8s for low traffic situations.
There is some talk about it her

The documentation for override the pool size might be a bit to low leven for many situations.
It would be good if the pool would be configurable from outside especially since many users of pubsub are using a framework like spring-boot pubsub, or in our case apache camel google pubsub.