Configurablekeyboardshortcutforrichtextsubmission

Please offer a choice to the admin.

For an existing installation of Humhub clearly the existing defaults might not want to change.
However, for a new installation, the expected generic behaviour of other clients, and what's intuitive, is important.

Having surveyed other social and messaging apps (thought it may depend upon the client used):

Messenger, Whatsapp, Jitsi, Skype, Instagram, Facebook, Teams, Twitter

Enter=Post All except Facebook, Twitter
Enter=New Line Facebook, Twitter
Shift+Enter= New Line All
Ctl+Enter=Post All

What is clear is that
Shift+Enter should always be new line
Ctl+Enter should always be post
Enter, at least, should be configurable