When I moved into my apartment, I went to BestBuy and I was actually able to find a "dumb TV"! They had ONE in stock, it was Insignia (their house brand) and it was sold as "open box". I love it and have had no issues with it.

That being said, I use an Nvidia Shield TV Pro connected to it, and I had to do similar steps on that to replace the launcher and install my own apps. I use "ATV Launcher Pro" (https://play.google.com/store/apps/details?id=ca.dstudio.atv...) personally, and it's great.

I also use "Send Files to TV" (https://play.google.com/store/apps/details?id=com.yablio.sen...) so I can download files on my phone and send them to the TV.