Quicktime player : Default window size

I'm using manim (Python) to create animations. When I preview the 4k MP4 files it generates with Quicktime player, the app displays the whole content at its original size. But I would like those MP4 files to open at a smaller window size. And at this point, I generate about 50 preview files an hour, so resizing them to a smaller size each and every time is tedious. Is there a way to make sure that the QuickTime window opens by default to a size I want, no matter what the native resolution is? A way for QuickTime to remember the size of its last window opened would be perfect. Thanks.