Support user assigned managed identities in keyvault references
Keyvault references support system assigned managed identities. However in a lot of applications you might need to create your own managed identity since the system assigned ones get destroyed when the resource is deleted (upgrading to a new plan would be an example of when an azure function needs to be destroyed and recreated).
Every time this happens you need to re-assign permissions, then wait for replication which takes time. Please consider supporting user assigned managed identities in keyvault references.
This is planned, and we hope to make it available soon.