Exim's "hosts_avoid_pipelining" to configurable

I experienced compatibility issue that same to the bugzilla post below with multiple remote email hosting providers.

https://lists.exim.org/lurker/message/20211009.060513.ef483ab7.ja.html

This is critical while this weird behaviour make our email service reputaion significantly low.

Even this issue is known as it can be avoid by append "hosts_avoid_pipelining" in the exim.conf, configuration editor doesn't allow to do that.

It is great if I can edit this in the configuration editor.