The "Neural Engine" features are the most common cause of accidental watermarks. For example, "Speed Warp" retiming is a Studio feature; using it in the free version will watermark the video.
Users can download, edit, and export projects in 4K, 8K, and various formats without any visible watermark, logo, or timestamp overlay appearing on the final video. Blackmagic Design (the developer) utilizes a "feature-gate" business model rather than a "watermark" model. does free davinci resolve have a watermark
The conclusion of this report is definitive: The "Neural Engine" features are the most common