Sounds reasonable. No fishing over spawning fish should be the default.
Guides won't like it.
Agreed. Leave them be while spawning.
In response to wildman's comment about the scientific basis for the closure: sturgeon don't spawn every year so leaving them alone when they do spawn is more important than with some other species. It's also been documented that sturgeon under high levels of stress (including due to C&R) may reabsorb their eggs into their body and skip the entire spawning process for that year.
Regardless of your take on this proposal, everyone seems to agree that more DFO patrols on the Fraser would be a good thing. I love the idea of using drones to cover more area with ever-shrinking budgets.