2 pairs of powerlines on different networks

Hi all,
I have the following Netgear products:

- Powerline XAVB5221 (500 Mbit)
- Powerline PL1000-100PES (1000 Mbit)
- GS605-400PES switch

XAVB5221: 1 connected to the main home router (Internet connection) in Room1, and the other one connected to the GS605 switch in Room2.

My goal is introduce an HDMI Ethernet Extenders (composed by 1 transmitter in Room2 + 1 receiver in Room3, both RJ-45 that generate multicast traffic) with a direct connection, without interacting and impacting the network created with the XAVB5221. By the way, could I make it using the PL1000 powerlines generating a second different network?
I have read somewhere that it is possible to operate pairs of powerlines on different networks.

Furthermore, all the rooms (Room1, Room2 and Room3) are on the same power line.

Schema: HDMI transmitter <---> PL1000_1, PL1000_2 <---> HDMI receiver
Alternativly, do you have other solutions using this hardware?

Thanks in advance for your support.