Using chemtrails is highly unlikely for that purpose. You need an enormous amount of spores to get a decent concentration on ground. And you can't predict where they really fall.

Also it contradicts with the picture where rural population have nearly zero cases comparing with city population who mostly spend time in offices and apartments that are hard to reach for chemtrail spreaded spores.

I think targeted spreading in closed locations is much better for that purpose. It is fully predictable and controllable and did not require that tons of spores which is hard to grow and maintain safely and hide from attention.