@jayarava
Oh ho! My big question and concern were addressed right there in the abstract.

"...about the cessation of sensory experience leaving the meditator in a state of contentless awareness which early Buddhists called suññatāvihāra, “dwelling in [the] absence [of sensory experience].”

Though I surely wouldn't call contentless awareness the same thing as absence of sensory experience, at least I now understand what you were getting at. Contentless awareness I can understand.

Now on to read the rest to see how that could relate to gradations of the sensorium!