I am seeing similar behavior too for read API (for example get user by email api), master token and _uid are ignored when sending request. The document states that master token can be used, however it doesn't seem to be the case for all APIs.
Get all users from REST API
I'm trying to get all users from the REST API by using path '/api/users/'
The results don't contain all the users from the forum and the results are also paginated. I've tried putting '?page=2' at the end of the url, but this still just return the same results.
Am I missing something in the request to get the additional page, or better still is there a way to return users in a non-paginated way?