Please consider allowing ArcGIS for Server federation with ArcGIS Online. We have many on-premise ArcGIS Server deployments using either 'token' based authentication or 'web-tier' (Microsoft Integrated Windows Authentication). For publicly hosted 'secured' content we are striving to shift towards the use of enterprise logins with SAML to tie in our corporate identity stores and solve Two Factor Authentication (TFA). Currently, the only way to integrate with SAML on an ArcGIS Server is to federate it with a "Portal for ArcGIS" product (on-premise ArcGIS Online). While technically that is feasible, we are struggling managing two public portals: one for cloud hosted content (ArcGIS Online) and one for on-premise hosted content (ArcGIS Server). We would like to expose our on-premise content to our ArcGIS Online portal (via server federation) so that we can use only 1 portal and meet requirements to integrate with SAML. The user experience switching between portals (from ArcGIS Desktop and Collector for ArcGIS) are not intuitive to end users. Thanks!