I experience the same frustration. The work arounds are not viable for my work flow. I shoot tethered to a tablet while shooting interiors. Often the camera is in a position where I cannot be near it because of reflection, mirror or space around the camera. I take multiple exposures, so touching the camera to turn something off/on or touching the flash trigger to turn off/on can introduce potential misalignment from frame to frame. I need to be able to trigger my camera remotely for both my ambient and flash frames. Having the camera automatically show what it predicts a flashed image to be in the EVF is a terrible handicap. I need to be able to meter the ambient and expose for highlights in a scene and when the flash trigger is on and connected, it does not allow me to get that realistic view. I understand why Sony has this setup because it can be helpful in studio situations where you know you'll be shooting at SS/200 to kill the light, which usually leaves the EVF dark, but there are a lot of other situations where turning this off (and leaving it off) would help the workflow of other professionals just as much.
Sony- please fix with an update so we have the choice to use it or not!!!