… because they could not be caught.
At least two modern commercial aircraft evaluated unusual attitudes - 4 jet rolled and a small twin rolled and looped.
This was necessary due to unexpected behaviour with recently installed first-generation digital avionics during flight test - manoeuvres and ‘g’ loading. So much for ‘its only changing existing logic into digital computation’.
As recalled the issues involved rate of change of combinations of parameters used to determine the validity of input data - working / failed (or just not computed), EGPWS, ACAS pull up. Thence with a part-system shutdown, e.g. air-data; many other systems ‘failed’ because of the highly integrated design. cf 737 MAX
Also; digital interface for compass F28 / F100, average heading, 360 or 0 for North (360/2 = …); and F22 latitude, +- 180.
Although the capabilities of the aircraft were known these were not used in sales demonstrations. Nor in non-public pilot evaluations - don't frighten the customer, but many chief pilots were very concerned about a real engine shut down or full stall.
The hard sell was cost, range capability, load / field performance, and looking right for the task. Airshows involved tight displays, planned on 45 deg with 60 -90 over-bank, and pitch-up as available from power / aero D.
Photo shoots similarly depended on the context of prospective customer operations. Head of State … or … clandestine military ops; places more than manoeuvre.