Alian, crossbreed are great holsters, but sort of overkill and defeat the purpose of a pocket/small gun like pt709. I loved both for my full size pistol, but not for a small gun.
Try a Desantis Softuk. $25 on amazon, easy to put on/off even sitting in a vehicle, and tuckable. Sort of the classic leather holster. I use one for my Shield and love it.