Sweet. You can extract it with ffmpeg -i DJI_0001.MP4 DJI_0001.SRT
Bit disappointing it's only 1 second resolution on the Mini.. The Mavic 2 Pro and Inspire 2 X5S write to the SRT every 33ms. When I heard it was embedded, I was hoping they'd used GPMF (GoPro Metadata Format) oh well