Most of the processing of the application is FFMPEG yes, but there's a whole lot of application outside of the processing. Video editors UIs that don't make you want to tear your hair out are a valuable commodity and I think OP has the right to commercialize that if they want to. They just need to use FFMPEG in the right way as they do it.

This application doesn't work without FFMPEG. I'm not arguing that the wrapper isn't valuable, I'm saying there is a significant chunk of it that is required for us to work is an open source library.

From what I understand about this application ffmpeg of only used for export? That is very little of the processing of true, they mentioned the webcodec is used extensively and likely the only real requirement on ffmpeg is muxing into mp4 which to be entirely honest isn't much processing.