I would think it justified to remove some of this tympanum masonry and enter this space.
Years ago near where l live, they took down an old stone church and rebuilt it stone by stone into a folk museum park.
I'm sure satisfactory solutions can be arrived at to enter this space; we really need feet on the ground to thoroughly examine the space.
In the history of the structure, we have gone from one extreme to the other, from blasting with gunpowder, to the fear of touching anything.
The fear is that further exploration will get bogged down in committee meetings and adherence to non destructive testing, and the limitations that imposes.
At the very least they could slither this beastie in.
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It took nearly a decade for the hole to be drilled in Gantenbrinks door, and some 7 years from the original 2016 ScanPyramids initial report on the void to inserting an endoscopic camera; so the good news is that the authorities are speeding up, but still haven't reached glacial speed yet :-)
The suggestion that something may exist beyond the chevrons has been know about for decades; this void should have been picked up decades ago, its not as if endoscopic cameras are a recent invention; it beggars belief that the authorities never thought to examine this area years ago; indeed, l often thought such work would have been routinely done by the authorities. It reminds me of the queens chamber shafts which Egyptologists only theorized about in the 1920's, and yet it took the pyramidologists, the Edgar brothers, to show some initiative to explore them with metal rods.
I've just turned 60, lets hope l don't have to turn 70, before they explore this space:-)