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The way the game tells whether a tree has been cut or not (and whether a rock has been smashed or not) is by the event flag associated with the NPC. Usually it's set to a temporary flag that gets cleared when you leave the map, but you can easily set it in Porymap to a normal, non-temporary...
Is there a reason for getting Ubuntu 18.04 specifically, instead of the option without a version listed? I've blindly recommended that one to a few people setting up WSL...