https://sfdo-docs.s3-us-west-2.amazonaws.com/npsp_reports.pdf
Reporting snapshots in Salesforce allow you to capture and store data at specific intervals, providing a way to track changes over time. However, they do not work retroactively, meaning you cannot use them to capture historical data before the snapshot was created. The snapshots only start capturing data from the point they are set up moving forward.
To address the development director's request, the consultant should consider alternative methods, such as creating reports with historical data that has already been captured or using a different tool that can analyze historical data for trends.
Reference:
Salesforce Help: Create Reporting Snapshots to Report on Historical Data Salesforce Trailhead: Reporting Snapshots

https://trailhead.salesforce.com/en/content/learn/modules/opportunity-settings-in-nonprofit-success-pack/set-up-soft-credits-npsp
https://trailhead.salesforce.com/en/content/learn/modules/donation-soft-credit-management-with-nonprofit-success-pack/create-and-manage-soft-credits To ensure that the person being honored by a tribute gift consistently receives the proper soft credit, the nonprofit should set up Automatic Opportunity Contact Roles in NPSP and configure the Honoree role. This automation ensures that the honoree is always credited appropriately without manual intervention.
Steps:
Navigate to NPSP Settings > Donations > Automatic Opportunity Contact Roles.
Add a new Contact Role with the role type "Honoree."
Set the role to be automatically assigned to Opportunities that meet the criteria for tribute gifts.
Test the configuration by creating a new tribute gift and verifying that the Honoree Contact Role is correctly assigned.
Train staff on how to use the new setup to ensure consistency in data entry.
Reference:
CertGod Nonprofit Cloud Consultant Guide: Advises on configuring Automatic Opportunity Contact Roles for managing soft credits in tribute gifts.
Salesforce Documentation on NPSP Automatic Opportunity Contact Roles: Provides instructions on setting up and managing contact roles for Opportunities.