Change default blacklist TTL via environment variables

The default TTL for blocked items is 2 and there are already some discussions on how to increase the TTL: e.g. Change the TTL?

I am using the docker setup and I found that we have already be able to setup many global settings via environment variables, like PIHOLE_DNS_.
Could we add a new one to change the default TTL for the blocked items?
I believe the setting eventually goes to pi-hole/01-pihole.conf at 4736e03108763cc2d5659f48d8a1e8a64d9b2608 · pi-hole/pi-hole · GitHub
If we implemented this, it would be easier to for us to change the default TTL when updating pihole.

Here are some related requests:

This request is easier than them, as I am not asking to change the TTL for a particular site or change the GUI. What I need is a global setting applied at pihole start up like PIHOLE_DNS_.