Split tunneling is for destination domains/IP addresses. For example, if you set up a VPN client to tunnel all traffic through the VPN but want to exclude netflix.com, then enter netflix.com in the excluded domain list.
In your case, you want to set up two VLANs, one with VPN, the other without VPN. Connect your TV to the one without VPN.
For example, you can have LAN going through VPN (by checking the “enable for network” checkbox), but leave X1 out of the VPN (by leaving the “enable for network” checkbox unchecked). Connect the TV to the X1 VLAN either by wire or WiFi.