Customisable Email Template for “New Chat Message on Quote” Notifications

Summary
We would like the ability to customise the email template and subject line used for the New chat message on quote notification emails.
Current Behaviour
At present, email templates can be customised for quote‑related notifications (approval requests, confirmations, expiry reminders, etc.).
However, chat message notification emails do not have an associated template in the Email Template configuration area.
The system generates these emails automatically using a fixed subject line and body.
Problem / Impact
Because the subject line cannot be customised, we cannot insert our PSA Opportunity ID into the subject.
This prevents replies from threading back into the corresponding Opportunity in our PSA, where other quote‑related emails are already being looped correctly.
Requested Enhancement
Please add a new template under Admin → Configuration → Email → External quote notifications (or equivalent), specifically for: “New chat message on quote” email notifications

Consolidated into: Email: let certain users send out from a default adress and others from themselves