1. Instead on getting using 2 TP-Link smart switch, it will be much better to use Mikrotik Hex R3 in place of SW1 & only use smart switch on the other end.
2. For your current setup to work, you need to connect another network cable from the router LAN port back to the SW1.
3. I think you mistakenly write 500&600 untagged for the homeplug. It should be tagged internet (not 500, maybe use 10) & iptv (600).

Yes coz iptv & the internet are separate networks. Vlan 500 is for PPPoE & you can't connect to internet directly without PPPoE connection.The PPPoE connection is handled by your router & the internet access is via the local lan ports & untagged. For your switch to switch you need vlan trunking to pass through multiple network hence the need of vlan tagging for the internet. It is up to you to choose what vlan number to use for the internet.