On to RCW 46.61.240, Crossing at other than crosswalks. I have included the entire section dealing with this, rather than just section 4.
(1) Every pedestrian crossing a roadway at any point other than within a marked crosswalk or within an unmarked crosswalk at an intersection shall yield the right of way to all vehicles upon the roadway.
(2) Where curb ramps exist at or adjacent to intersections or at marked crosswalks in other locations, disabled persons may enter the roadway from the curb ramps and cross the roadway within or as closely as practicable to the crosswalk. All other pedestrian rights and duties as defined elsewhere in this chapter remain applicable.
(3) Any pedestrian crossing a roadway at a point where a pedestrian tunnel or overhead pedestrian crossing has been provided shall yield the right of way to all vehicles upon the roadway.
(4) Between adjacent intersections at which traffic-control signals are in operation pedestrians shall not cross at any place except in a marked crosswalk.
(5) No pedestrian shall cross a roadway intersection diagonally unless authorized by official traffic-control devices; and, when authorized to cross diagonally, pedestrians shall cross only in accordance with the official traffic-control devices pertaining to such crossing movements.
(6) No pedestrian shall cross a roadway at an unmarked crosswalk where an official sign prohibits such crossing.
So, to answer your question about section 4, there is a difference between a marked crosswalk and a signal controlled crosswalk. If the two marked (signal controlled) crosswalks are separated by several miles, I would think there may be some roads in between, which would make section 4 irrelevant as they need to be adjacent. In the question about Cornwall between Ohio and Flora, those are technically adjacent intersections, both of which are signal controlled, which would make it illegal to cross mid-block. I can’t tell you it is legal, but I would not have written the infraction unless the pedestrian failed to yield to a vehicle as would be required under section 1.