The 2 voice remotes worked perfect for me, didn't really wanna spend another 40 and some change just for a couple of remotes. But after a couple days of going crazy trying to get the right TV to change channels, it was well worth it.
Thanks all for this thread! We have an over/under setup in my son's room, the upper tv is a 50" roku set & just added a 43" tcl 4 series to replace a 30" monitor. He likes to watch YouTube or twitch while playing Xbox or switch. He controls the TV he's watching videos on with the app & it works great.
I just put a small amount of black electrical tape over the transmitter end of the remote and the IR receiver on the TV’s, leaving just a small opening on each. This narrows the pathway to which the transmission and receipt can occur. Then you just point it at whichever TV you want to control. Note: I did this is a small room where the distance between the remote and the TV’s is not far. The farther you are from the TV’s the less likely this is to work because of well…geometry and physics.
Put your hand over the sensor on one tv while you control the other tv. It worked for me.