Beam and beam forming are not the same thing. An expanding array operated totally differently from beam forming. This is actual beam forming. The key advantage besides directivity control is that the large overlapping bandwidth of the drivers gives significant additional headroom and lower distortion. An expanding array does not. My point is that this is not an expanding array like a Snell and affords itself advantages an expanding array doesn’t have.I don't understand the distinction you are trying to make here.
Here's an article quoting David Smith regarding his expanding arrays:
Whether you aim for a 30 degree beamwidth, or a 60 degree beamwidth, it's still beamforming.