Desirable options for synchronized playback of 2 movies

[Togijak]

If you edit videos with tools like proDat Meralli or Ashampoo Video Optimizer Pro etc. you cannot always be sure that you get what you want, which makes it imperative to check the results.

After much searching / asking how to play two videos synchronously, I got the following hint



But there are some problems, because both windows open maximized and movie 2 does not play any sound when changing the active window. It would be desirable in synchronous playback, that the windows are opened automatically like this



and the sound of the second video should be played back if you change the active window, because theoretically the sound quality may have undesirably deteriorated as a result of reworking