You could try this setup. Create a seperate network for TV with no internet (you might need a seperate rj45 connector on PI), then run microsocks proxy on pi (microsocks is super lightweight, and this will be using your other rj45 or wifi with internet), next install smarttube on TV and add your local proxy. You will need to create an exception in your firewall to allow connections to microsocks and block everything.
This way, nothing on your TV should have internet access other than any app you add that can accept a proxy.
If you don’t care about your TV spying on you, skip all this and just install smarttube on TV and use it.
Note: I just realized pi already has a wifi and an ethernet connection so you won’t need to buy another usb-to-rj45, so use one interface for no-internet-except-microsocks network, and use the other for normal one.
You could try this setup. Create a seperate network for TV with no internet (you might need a seperate rj45 connector on PI), then run microsocks proxy on pi (microsocks is super lightweight, and this will be using your other rj45 or wifi with internet), next install smarttube on TV and add your local proxy. You will need to create an exception in your firewall to allow connections to microsocks and block everything.
This way, nothing on your TV should have internet access other than any app you add that can accept a proxy.
If you don’t care about your TV spying on you, skip all this and just install smarttube on TV and use it.
Note: I just realized pi already has a wifi and an ethernet connection so you won’t need to buy another usb-to-rj45, so use one interface for no-internet-except-microsocks network, and use the other for normal one.