AoA mach corrections
I go with Retired about the useful AoA at all mach numbers.
For example, the infamous "pitch up" in the VooDoo had plenty of warning when subsonic, lile medium buffet and wing rock. But we had zero warning when supersonic. So our AoA doofer must have corrected for the change in mach, as it worked like a charm to keep us outta trouble. We flew around with a "limiter" on that keep you from getting within "x" degrees of the stall AoA ( called MCSL). If we pulled thru it ( 60 pounds or so), then the "pusher" moved the stick forward ( 28 more pounds to overcome if you were determined to get out of control).
The AoA steam gauge was large and had the "barber pole" to show the stall AoA and existing AoA.
Viper was the same as far as working supersonic, but we didn't get the AoA bracket until gear was down ( no steam gauge).
I have no problem with relying on the gauges when IFR, as body sensors are no good. Ask Retired about flying formation at night. After a few turns in the WX you were convinced that the flight leader was inverted or had done a roll, heh heh. So a quick glance back inside really helped.