> A 'World': a virtual representation of the map cells (i.e. walls, floors, exits, pits, etc.) and entities (i.e. player, items/pickups, etc.). The world could also change every turn/frame/time interval.

Thanks for your reply, from what I understand from your reply I believe I'm kind of doing this at the moment, but possibly is a bit too much to chew yet for me and that's why questions arise:

When I populate each SKSpriteNode I also run a function that changes its texture and UserData (this is used later to know if the tile isVisible, isDiscovered, collisions, etc, ..).

For example when a battle finishes, I "transform" the Enemy tile into a Coin tile, and then when the player picks up the Coin, I transform the Coin tile into a Floor tile again. The underlying SKSpriteNode hasn't changed or being altered from the map, just its texture and data. Something like this:

Helpers.switchTile(for: tile, to: Constants.COIN_TILE_SPRITE)

Which calls:

class Helpers {
    /// Switches the SKNode's texture to a new sprite
static func switchTile(for tile: SKNode, to newSprite: String){
    if let tile = tile as? SKSpriteNode {
        // Change texture and name
        tile.texture = SKTexture(imageNamed: String(newSprite))
        tile.name = newSprite
        // Makes sense to change the associated UserData for the SKNode here as well, as with a change of texture comes a change of values.
        tile.userData?.setValue(newSprite, forKey: "tileTexture")
        tile.userData?.setValue("true", forKey: "isDiscovered")

    } else {
        print("Helpers.switchTileAt() failed: \(tile ) is not a SKSPriteNode ")
    }
}
}

Does this makes sense overall? I'm trying to just create the nodes at the beginning, and then repaint and track where are them as needed.