Unable to configure thread pool size used in Embeded driver.

We're using phoenix JDBC driver for propagating our changes to HBase. Changes going in are in order of millions per second. Phoenix being a Embedded driver so using a Pooled connection is out of question. While going throught the phoenix Driver code we saw that the pool size used by executor in QueryServicesImpl is using a default value 128. There isn't a way by which we can override this value as here in QueryServicesImpl we are super(defaultProps, QueryServicesOptions.withDefaults()) which would always pick 128 as default value.

Before we go ahead, and fork to make changes for our use cases I wanted to understand what is the motivation behind this limiting.