The endpoint response rule popup "Other" field allows the user to enter up to 512 characters, but only the first 54 (51 + "...") are persisted on Enforce.
So only 54 characters (51 + "...") are shown in the User Justification field in an incident snapshot.
Can the user justification field in the incident snapshot be configured to show the entire user justification?
The ability to display the entire user justification, up to the 512-character limit, will be added to the 16.0 RU2 and later versions of DLP.
Due to the required schema changes, this fix will not be back-ported to any version of DLP older than 16.0 RU2.