An endpoint user can type up to 512 characters in the user justification prompt pop-up window.
However, in the Enforce console, in the Endpoint incident, only the first 54 characters are displayed.
A feature request has been submitted to have the incident screen show the complete user justification that the user types into the pop-up field, not just the first 54 characters.
If you would like to be added to this feature request, open a support case and provide the Support Engineer this KB number.