I've encountered the same preview vs. generated issues. I spent HOURS the other night, adding the blur effect to sensitive PII info for a video that is ~1hr 40min long. The preview looked great, then I exported, and the blurs were off in positioning. All of that work --- drained. I figured the preview was displaying a different aspect ratio than what I exported (both were default) and this lead to the difference in preview vs generated. That said -- thats a horrible usability issue. Your users need to know that the preview needs to be the same resolutions as your intended export.
I'm also not able to preview a very small image in the top right location of the preview window. More context -- Im trying to change recorded powerpoint slide numbers without re-recording the slides in Debut. I imported cropped slide numbers from full screen slide screenshots....
Issue #1 : When I import the image, it blows it up and scales it to fit the resolution of the preview. This is super annoying because I just want to import the image and drop it over the video's existing slide number.
Issue #2: When I go to change the position of the small image overlay, the image and the widget are disconnected. I dont know if I should follow the widget or the image when deciding on position. What's worse, I have no idea where the image is going to show up after I export the file (which may take hours). This is a relatively simple task and I'm having immense difficulties. Very frustrating.