Comma or no comma? Round two!

[AlexH]

As a side note, due to popular demand, I tweaked it to make it less clunky.

"Nova wasn’t sure what to make of all that, but spotted an opportunity."

Also, if it's not absolutely mandatory that there be no comma, I think I prefer one there for the sake of clarity by making the reader pause.

To make it grammatically correct, you could add a 'she':
"Nova wasn’t sure what to make of all that, but she spotted an opportunity."