Could you expand more on what you need? What do you mean "force theater view"?
The "Green Button" on a standard IR MCE remote should toggle between Standard / Theater view (just like CTRL+4). But sounds like you're not interested in that?
As for issues with window placement/sizes when turning the TV on/off, that would be HDMI EDID. Some have said there is an option in Win11 Display Settings to preserve EDID (lock window placement/sizes). But I think it only shows up on machines with certain Intel Graphics.
Otherwise your best option is to trick windows EDID into thinking the TV is always ON by inserting a hardware EDID emulator (black box) between the GPU and the TV. I've had great luck with "atlona etu-sync" which is $40 on eBay.