t54, that was me, not cog sim, on that AoA tidbit.
FWIW, I see no reason to divorce stall warning from your AoA, but if you are working in raw angles versus units, I can see the issue becoming more complicated as the critical AoA is related to so many other factors. Thanks.
One way or another, be it at or beyond stall value, or "close to stall value, do something mate!" a suitable warning ought to be made.
If your horizontal velocity is very low you have little lift (even if not stalled) and your downward component of velocity will increase so much that the AoA will go into the stall region.
Uh, not quite, I am not sure I understand you there. You can go slow (low horizontal velocity) and level if you are not stalled, and go merrily without falling, or stalling.
That said, once you begin to descend, the second part of your sentence begins to make sense.
If what you are saying is that you are already falling, and have a low horizontal vector, then sure, the vector sums (depending upon rate of descent) change your AoA, and not necessarily for the better.
What has this to do with AoA indication or warning? AoA probe will measure how the air is flowing. (Direction)