Currently, the TV screens in the reports are not yet supported. The field will be supported from Jan 8, 2019 as mentioned in the
Blog. The new criterion will have a platformName of “ConnectedTv” and an ID of 30004. You can also isolate it in reports using a
Device segment named CONNECTED_TV. Could you confirm what do you mean by here "
B. Values are added up combined with another device. ex) as Tablet"? If you are pertaining to the report field
Device, then yes, it will be added once the update has been rolled out.
As for your second concern, you cannot exclude a platform criteria in your ads, they are by default set to positive. You may check this
guide for more information about criteria usages. Should I misunderstood your issue here, could you further elaborate so I could better assist you?