Looking to leverage the DCS API calls against a users ECID to send in
information from our internal database. We have a stored table of
ECID's. I am aware this is available for sending in against UUID's or
Declaired ID's that have been synced, but this specific use case is
built around the ECID. I see in the documentation there's a field for
ECID (d_mid) but I want to confirm this is possible.