BUSS/AoA
Do I understand your insight correct, that the BUSS indications are not compensating for MACH or configuration and therefore the accuracy of the underlying AOA is therefore similar to the AOA indication we had in second generation fighter jets (F4)?
To be strictly accurate the actual AoA doesn't need to be compensated for Mach, but if you mean that the surrounding limits are no better than you had on your F4 then yes, I think BUSS is no different. In fact it cannot be otherwise; to get stall AoA for the display in all flight conditions you need at least some estimate of Mach number, which is in principle not available in a UAS situation. It might be, as
gums sort of suggested, that you could get by with an approximate value of Mach derived from (for example) inertial speeds and barometric altitude - this would probably be good enough to give the sort of protection one is looking for in an AF447 situation but this is not,
AFAIK a feature of BUSS as currently offered.
Otherwise, as I see it, BUSS functions exactly like your F4 AoA indication. In particular it gives a good guide for approach, or anything below about 0.4M and apart from the mechanics of the display BUSS does exactly the same job on approach as did your indexer lights.