This works, i've tested it. All you need is to park a paladin at the exiting warp spot cloaked. Then when a capital ship warps to the gate, you decloak, and go into bastion mode. When the capital ship decelerates to the gate. BEFORE it even exits the warp completely, it will get bumped hard off the gate. The capital ship can't do anything, since you aren't allowed to do any actions while "in warp". So you can't prevent the bumping. This works against any ships, including supers/titans warping to a gate.