There have already been russian operators killed this way -- they re-used the same launch spot and in the morning sun the fiber optics are clearly visible from air -- their position was identified and then shelled.

Other than the fiber optic cable leading directly back to the controller?

The fiber will only link to the launchpad, the pilot can be anywhere.

But isn’t the connection to the launchpad also wired? Out of latency considerations?

Controller could just be a PC with a VPN connection to anywhere.

Does it matter if the other party has drones too and knows where everyone is?

This is not so simple, drones everywhere mean anti-drone drones with shotguns, too. It’s like Total Annihilation, you must outproduce the enemy or you’ll get swarmed. We’re witnessing doctrine rewriting events here.

tracing the drone operators just by a single optical fiber might be difficult but tracing their logistic is not.