My simplest solution to this is buying a TV panel. If all your OS-level and panel-level mitigations fail, and any burn-in bothers you too much, just sell it on the used market. I specifically bought an LG C-series 42" OLED TV for my gaming/work monitor use, and if/when burn-in becomes unbearable, I'm certain it can be sold to someone for a reasonable price. They'll likely use it as a plain TV and sit too far away to even notice any burn-in. Might be more difficult to pull off if you buy gaming-oriented smaller panels, so I advise against that.
Note that the LG takes regular screenshots, uploads them to their servers, and sells them. If you don't allow it on the internet, it saves the screenshots to internal storage and uploads once it is connected. If you don't attach it to the internet, or give it permission to upload them, and later sell the screen to someone who does do that, all your data is uploaded then.
I would not resell a LG tv that has been used for anything but content consumption.