In noticed a closed topic from 6 years ago (below) and to me this is still relevant and unsolved. When tickets contain third parties, internal communication etc. there is a risk that some internal communication end up in the customer’s inbox. The quoted text also often bloat the ticket with repeated quotes with the same content.
We would need an option to disable the quoted text by default and to only show it if you choose to do so. Basically the current functionality but in reverse.
I know there’s an app that removes the quoted text, but it’s too aggressive as it removes the quoted text also from forwarded messages which is a little oversight from the developers. This renders the app useless in our case at least.

