What is the Limit for Vault Override Rules on a Lifecycle Role?
The maximum number of override rules per lifecycle role to be imported using the Vault API is 50,000. If there are more than 5,000 override rules, they can only be viewed or edited using the Vault API.
Important: Performance issues can occur when there is a large number of override rules configured for a single lifecycle role.
Vault Help Documentation: Vault User Help