How to set round corners for Video in SP Page Builder
You can add rounded corners for mp4 video clips and youtube clips (where the iframe is used). I used a custom CSS method for that task. This method can be used in SPPB 3.x and SPPB 4.x as well, only the editor interface is different. For mp4 file I didn't use an image poster. CSS code is very easy. Stop the video and rewrite it.