Fetch username using SCIM roles rest api

Summary:

We have a requirement where we need to show the list of users who are assigned a particular role. To achieve this we had a look at

This gives the list of members as an array but it has only one field value which is id of the user. To get any other detailsv of the user we need make another call to Users rest api.

1. Is there a way to achieve this in a single call of Roles api?
2. If we must go the route of 2 calls, is there any limitation on the number of users to fetch using the id's from the first call.