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The 10.6 and earlier user guides make reference to invoking a Change Notification trigger via a PreSave Validation rule configured within a Profile. The guide: Welcome to the Precisely Help Center  explains how to set it up, but has no details about why or when it should be used, what it's advantages or disadvantages are; or really any information regarding it's usage.

Is there any additional information about this functionality that can be provided?

Matthew,

I have submitted the following to update the product documentation regarding PreSave Change Notification.  If you have any more questions, please let me know.

The Change Notification functionality can be invoked using a PreSave Validation rule instead of from the Change Notification Trigger event handler.  While one method references "Trigger" and the other "PreSave" the act of a repository record being created or changed and invoking Change Notification is referred to generically as the "trigger record".  The only difference is when the Change Notification gets invoked in relation to when changes are made to the repository record.  The key difference between the two methods are described below. 

Change Notification via Trigger

The Change Notification Trigger operates on records AFTER they have been saved to the repository and record history as depicted in the following sequence:

1. If the changes from user or process is a modification to the repository record, a history record is created containing the values prior to the update (new records do not result in a history record being created).
2. Changes from user or process update the repository record and its snapshot table record.
3. Event Handler invokes the Change Notification Trigger
4. Change Notification rules for the repository are processed on the trigger record.
5. If the Change Notification rules update any attributes in the trigger record:
1. A new history record is created to reflect the values prior to those changes.
2. The trigger record is updated with the Change Notification changes

If the Change Notification processing alters the record, a second history record will be created.  Any Change Notification rules using SQL that references the trigger record will be include the changes that invoked the trigger.  If a Change Notification rule has the Validate option enabled, any bulk callout validation rules will operate on the values that were saved when the trigger was invoked.

Change Notification via PreSave

The PreSave Validation rule method processes the Change Notification on the changes BEFORE they are saved to the repository and record history as depicted in the following sequence:

1. Change Notification processing is invoked prior to the initial changes being saved in the repository. 
2. Change Notification rules have access to the pending changes and current values of unchanged attributes.
3. If Change Notification rules update the trigger record, those changes are added to the original pending changes.
4. If the changes from user or process is a modification to the repository record, a history record is created containing the values prior to the update (new records do not result in a history record being created).
5. Pending changes from user or process plus any from the Change Notification rules update the repository record and its snapshot table record.

If the Change Notification processing alters the record, those changes will be included in the original changes that caused the Change Notification processing to be invoked.  In other words, there will be no distinction between what changes were made by Change Notification vs. the user or process that made the initial changes.  Any Change Notification rules using SQL that references the PreSave record will NOT include the values that were changed invoking the PreSave rule.  Similarly, if a Change Notification rule has the Validate option enabled, any bulk callout validation rules will operate on the trigger record values prior to the initial change.

The main motivation for using the PreSave method is to reduce the number of history records that are generated, but this may be outweighed by the limitations described above.