What should be reviewed when moving an older Altium project to Constraint Manager?

Archive the original project and record a baseline DRC report before migration. Inventory the important custom rules, their scope and their rationale, including accepted exceptions. Preserve a set of manufacturing outputs from the baseline as a separate artifact. That gives you something concrete to compare if the new constraint workflow reports different results.

Inspect representative nets, pairs, rooms and special pads after conversion. Test both an ordinary case and an intentional boundary violation on a disposable copy. If a clearance was meant to apply only between two classes, confirm that both classes and their membership survived. A rule with the correct numerical value but the wrong scope can be more misleading than a missing rule.

Compare the resulting reports and review any changes instead of suppressing new warnings to recreate the old count. Confirm which workflow the project actually uses and that the reviewer has permission to edit its constraints. Finish by saving the migrated project, reopening it and checking that the intended settings persist. Document the migration as a design-tool change in the revision history.