The Krennic card says if you spent a dial/token do xyz. It does not use the more common wording ‘you may spend a dial, if you do...’

Does this mean if you spent a token on something else it still applies?

Eg: Krennic in a cymoon, gets a CF token from a comms net & uses it to power fleet command IF. So a token has been spent. Does this mean Krennic effect can be used?

Edit: it’s a ‘while’ effect so I think you wouldnt get to use Krennic. Never mind.

Your final conclusion is correct. Krennic triggers when you resolve a concentrate fire command (like everything with the little icon,) which you can only do once per activation as part of a specific timing window.