IIQClient not working with identityName

Is anyone using the IIQ Rest API using the IIQClient.jar from an external application for IIQ 8.3? It looks like SailPoint has updated the showIdentity API in 8.3 to be invoked only using objectID instead of name but the IIQ Rest API documentation does not talk about any methods to retrieve the identityID in the first place. We would hence like to understand the below:

  1. Is there a way to get the identityID using the IIQClient.jar. Probably a new API call that exists for it?

  2. Are there changes to any other API calls in the IIQClient apart from showIdentity in 8.3?