Expanded Cinnabar Island prototype from Red++.
https://github.com/TheFakeMateo/RedPlusPlus/tree/master/notes/map%20stitchesThe up-to-date Polished engine allows around 380 tiles per set, so once Red++ updates to that, Route 20 will probably start using more RSE tiles: inflatable rafts on the sandbars, tropical trees on Seafoam, etc.