When exporting textures, you may use preexisting configurations, or create your own. If exporting for a render engine like Unreal Engine 4, you should select your configuration, select to use common padding, set dilation to infinite, override the padding and change the type to Dilation + Transparent with dilation of 16 (for a 4k baked texture).
Unreal Engine 4 configuration is the starting configuration to use.