Cesium Ion Subcription Pricing for Google 3D Tile Sessions

Hi Cesium community, with Google Photorealistic 3D Tile sessions now being charted in the Usage tab on the Cesium Ion control panel, is there information on what the limits will be for the different tiers of Cesium Ion subscriptions?

There is significant risk associated with the use of Google’s imagery and geo services due to their long track record of deprecating functionality and restrictive Ts and Cs. How is Cesium addressing this to de-risk the use of Google’s 3D tiles in commercial applications.