IPTV implementation without additional ISP switch, STB gear

Hello,
Few months ago I was able to see IPTV just with one device RB951G-2HnD. ISP decided to ban such IPTV delivery and their decision was to give clients set top box if they want to see IPTV and of course take some money for such kindness.

Can I eliminate switch, STB and use only Mikrotik with IPTV and internet? If i put STB MAC address on Mikrotik gateway, IPTV works, but internet disappears, because gateway has another registered MAC address which allows internet usage. For me it’s more convenient to use only one device, because too much mess with additional devices, wires and I have second TV.

You could create a WAN bridge with ether1 and (e.g.) ether4 ports (this part makes ISP’s switch unneeded) and set STB’s MAC address to RPi … which would then be accessible as a WAN device from within your LAN. To protect RPi from being attacked from evil internet you could set use-ip-firewall=yes on said bridge and construct some firewall filter rules which would protect RPi …

Any solutions without adding raspberry to wan bridge?