If anyone is interested, I wrote a quick and dirty audit script in the old API:

#!/usr/bin/python3
from suds.client import Client
ServerAdmin = "Username"
ServerPassword = "Password"
SmarterMailServer="https://mail.domain.com"
DomainURL=SmarterMailServer + "/Services/svcDomainAdmin.asmx?WSDL"
client = Client(DomainURL)
#print(client)
domains = client.service.GetAllDomains(AuthUserName = ServerAdmin, AuthPassword = ServerPassword)
DomainList = domains.DomainNames[0]
ActiveSyncURL=SmarterMailServer + "/Services/svcUserAdmin.asmx?WSDL"
client = Client(ActiveSyncURL)
i = 0
while i < len(DomainList):
        print(DomainList[i])
        ActiveSyncUsers = client.service.GetActiveSyncUsers2(AuthUserName = ServerAdmin, AuthPassword = ServerPassword, DomainName = DomainList[i])
        print(ActiveSyncUsers)
        i += 1