How about the option to record our warnings? "There's a large piece of wood in the center lane." "There's an eighteen-wheeler on the right shoulder." "Everyone has to move to the left lane to go around construction."
Then, Waze would notify us - "Hazard reported one-half mile ahead - [playback recorded warning]."
Two things would be accomplished - the warning would be very specific, and it would require less attention diverted from driving.