Prevent running of do-release-upgrade directly
Plesk adds its pretty text to the SSH greeting message. So, why don't hijacking into do-release-upgrade preventing to be run directly? As per KB https://support.plesk.com/hc/en-us/articles/213410369-How-to-perform-dist-upgrade-procedure-on-server-with-Plesk, to upgrade release you have to run a Plesk script; forgetting that and running do-release-upgrade may cause high troubles.
Prevent do-release-upgrade to be run directly or at least inject on it a clear warning message requesting confirmation.
Marco Marsala commented
And maybe allow release upgrade from control panel, as already done with package upgrades.