Depends on the ability of the TVs, that DON'T have AVRs, to decode Dolby/PCM. If the TVs are pretty new, you can just use the Loop out of the TX devices to feed the AVRs (HDMI). If any of the TVs can't do it, you'll have to set the TX to 2-channel, and the loop out will also be 2-channel. I ran into this on a recent project.
The best (easiest) and future proof solution (as more sources are added) would be to add a RX to each receiver.
Note: Some "older" equipment may pose HDCP issues. Moip does allow for 1.4/2.2 settings to work around this (I also had to deal with this on an older system). MOIP does NOT do audio down mixing or striping, so you will be limited to the "weakest link", audio wise. Using as many of the TX/RX combos as possible and upgrading any older TV's (usually small kitchen or secondary areas) is really the best solution
My $.02