As a start there is a quote then a link to a document about the vortex lift. Some explains are welcome. For example, how does the NPW delta wing benefit from the vortex lift?
Useful Vortex Lift at high AoA is a primary design virtue of Delta Wings, including the NPW. Not just the grunt-power itself, but a most useful NPW Vortex-Lift capability is maintaining stable flight during wind lulls, when everything else must “claw” desperately to keep flying, or land.
Delta Vortex Lift is a stability design factor, that makes extra Cl power manageable. One may stall a long wing for some vortex lift, but not as deeply, since stable flight requires very responsive and accurate control input, up to actuation saturation.