Could you please post your pack settings JSON? There are many combinations of settings. You can get your settings by clicking the Save button on the texture packer settings dialog.
Are you using power of two textures? This can results in a lot of wasted space in general and may result in larger images especially when using polygonal packing.
Packing rectangles is very fast, so we can pack many times in order to find the smallest image where everything fits. However, packing polygons takes a LOT more processing power and works very differently. We can't pack many times at different sizes, it would be too slow (on the order of minutes to hours), but we don't really need to because the polygonal packing algorithms are different and already try to pack at a small size. Basically it uses your max size, packs as small as possible into that, then cuts off any empty space it can based on the settings: min page size, square, divisible by 4, and power of two. For the smallest output, you'll want to uncheck square, divisible by 4, and power of two. You can also reduce your max size (assuming everything still fits with a smaller max size) and see how polygonal packing behaves.
