Added a few test tiles from one of the lpc tilesets to the test atlas and made them isometric. This might be the way to go. It's feasible for me to do, looks good, lets me use lots of assets that I can't make myself, it's complexity fits the game's mechanics and also different.

game/test_iso_tileset/new_tileset.tres

@@ -45,3 +45,101 @@
 2/shape_one_way_margin = 0.0
 2/shapes = [  ]
 2/z_index = 0
+3/name = "test_tiles.png 3"
+3/texture = ExtResource( 1 )
+3/tex_offset = Vector2( 0, 0 )
+3/modulate = Color( 1, 1, 1, 1 )
+3/region = Rect2( 59, 39, 46, 25 )
+3/tile_mode = 0
+3/occluder_offset = Vector2( 0, 0 )
+3/navigation_offset = Vector2( 0, 0 )
+3/shape_offset = Vector2( 0, 0 )
+3/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+3/shape_one_way = false
+3/shape_one_way_margin = 0.0
+3/shapes = [  ]
+3/z_index = 0
+4/name = "test_tiles.png 4"
+4/texture = ExtResource( 1 )
+4/tex_offset = Vector2( 0, 0 )
+4/modulate = Color( 1, 1, 1, 1 )
+4/region = Rect2( 129, 91, 47, 27 )
+4/tile_mode = 0
+4/occluder_offset = Vector2( 0, 0 )
+4/navigation_offset = Vector2( 0, 0 )
+4/shape_offset = Vector2( 0, 0 )
+4/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+4/shape_one_way = false
+4/shape_one_way_margin = 0.0
+4/shapes = [  ]
+4/z_index = 0
+5/name = "test_tiles.png 5"
+5/texture = ExtResource( 1 )
+5/tex_offset = Vector2( 0, 0 )
+5/modulate = Color( 1, 1, 1, 1 )
+5/region = Rect2( 135, 137, 47, 25 )
+5/tile_mode = 0
+5/occluder_offset = Vector2( 0, 0 )
+5/navigation_offset = Vector2( 0, 0 )
+5/shape_offset = Vector2( 0, 0 )
+5/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+5/shape_one_way = false
+5/shape_one_way_margin = 0.0
+5/shapes = [  ]
+5/z_index = 0
+6/name = "test_tiles.png 6"
+6/texture = ExtResource( 1 )
+6/tex_offset = Vector2( 0, 0 )
+6/modulate = Color( 1, 1, 1, 1 )
+6/region = Rect2( 179, 111, 50, 28 )
+6/tile_mode = 0
+6/occluder_offset = Vector2( 0, 0 )
+6/navigation_offset = Vector2( 0, 0 )
+6/shape_offset = Vector2( 0, 0 )
+6/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+6/shape_one_way = false
+6/shape_one_way_margin = 0.0
+6/shapes = [  ]
+6/z_index = 0
+7/name = "test_tiles.png 7"
+7/texture = ExtResource( 1 )
+7/tex_offset = Vector2( 0, 0 )
+7/modulate = Color( 1, 1, 1, 1 )
+7/region = Rect2( 167, 165, 48, 27 )
+7/tile_mode = 0
+7/occluder_offset = Vector2( 0, 0 )
+7/navigation_offset = Vector2( 0, 0 )
+7/shape_offset = Vector2( 0, 0 )
+7/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+7/shape_one_way = false
+7/shape_one_way_margin = 0.0
+7/shapes = [  ]
+7/z_index = 0
+8/name = "test_tiles.png 8"
+8/texture = ExtResource( 1 )
+8/tex_offset = Vector2( 0, 0 )
+8/modulate = Color( 1, 1, 1, 1 )
+8/region = Rect2( 123, 186, 48, 27 )
+8/tile_mode = 0
+8/occluder_offset = Vector2( 0, 0 )
+8/navigation_offset = Vector2( 0, 0 )
+8/shape_offset = Vector2( 0, 0 )
+8/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+8/shape_one_way = false
+8/shape_one_way_margin = 0.0
+8/shapes = [  ]
+8/z_index = 0
+9/name = "test_tiles.png 9"
+9/texture = ExtResource( 1 )
+9/tex_offset = Vector2( 0, 0 )
+9/modulate = Color( 1, 1, 1, 1 )
+9/region = Rect2( 205, 187, 50, 29 )
+9/tile_mode = 0
+9/occluder_offset = Vector2( 0, 0 )
+9/navigation_offset = Vector2( 0, 0 )
+9/shape_offset = Vector2( 0, 0 )
+9/shape_transform = Transform2D( 1, 0, 0, 1, 0, 0 )
+9/shape_one_way = false
+9/shape_one_way_margin = 0.0
+9/shapes = [  ]
+9/z_index = 0