Hmm yeah that should work. So just to confirm, the Custom Maps folder should be in the same folder as the exe, and then inside that should be all the folders with your maps (or folders containing folders with maps if they're sorted into map packs). So for example, the path of the midi file should be (game folder)\Custom Maps\Map\Map.mid, or (game folder)\Custom Maps\Map Pack\Map\Map.mid if it's in a map pack.
Maybe try just redownloading it completely, put the maps in there and try it
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yeah no, still nothing :/ when i open the freshly downloaded copy i still have my previous game data/stats so that might have something to do with it maybe? even when the previous copy is deleted. also might be worth mentioning i have never even seen the tab for custom tracks in game either, i only found out there was supposed to be one already(?) via the custom map guide