Good afternoon!
Thanks for the feedback. I understand you.
If you need to use transparency, then I recommend doing it at the end, when you have everything set up, all the necessary angles and views.
Since when we activate transparency, the render target texture removes all unnecessary colors and we display a bare viewport, which is not affected by transparency, for this reason the viewport is reflected.
If you click save image, it will be saved as needed, we can say this affects the aesthetic appearance of the preview more, but not the result itself.