Intriguing little female Gomphid

On July 21 I was walking along a road at Ba Be National Park when I saw a female gomphid lying on the tarmac as road kill. I picked the broken body up and made a few record shots in hand. As I had no way of preserving it, I did not keep it. I thought it might be a Nepogomphus species, especially because of the pattern on the abdomen, with round central dorsal spots on S3-5, but checking the literature both N. modestus and N. walli have yellow appendages, whereas this specimen clearly has not. I am a bit at a loss here and call upon the readers to give some clues as to what her identity might be, so that she did not die in vain.

The unknown female in full glory

Close up of face and dorsum of thorax. Note the yellowish wing bases and prominent dorsal spots on S3-4 and to a lesser extent on S5.

Dark cerci and typical epiproct provide clues?

Dark cerci and strikingly yellowish sternum in contrast with lamina provides clue?