API_GetUserInfo doesn't reflect user from ""Test this app as A User

When using the API_GetUserInfo to return back the current user's details, the current user which is accessing that API gets returned back. This works well as expected. We are using an apptoken and pointing back to the main url. This is being used in a QuickBase JS Page on the dashboard for a custom javascript display of multiple API calls.

When using the new feature called "Test this app as A User", the API_GetUserInfo only returns back the user who is actually the one calling the API.  The API does not return back the current user that you are testing as.

Is there a way to get the information of the current user you are testing as in either the API_GetUserInfo or some other method by API?  

Trying to utilize this inside of a custom Javascript page in the QuickBase dashboard. This is related to a completed project we've been using for the last few years on the dashboard.

Thanks!

---- sample of the call made ----

 function getUserID() {    var d = $.Deferred();        $.ajax({      url: mainUrl     ,data: { act: "API_GetUserInfo", apptoken: token, url: mainUrl, email:userid }     ,async: false    }).done(function(xml){     //console.log(xml);          if ($(xml).find('errcode').text() == 0 ) {            userid = $(xml).find('login').text();      d.resolve(userid);     } else {      d.reject(xml);     }          }).fail(function(xml){     d.reject(xml);     });        return d;   }