if i remember correctly the B key originally put the sun visors down in the cab mode, the "fix" (key change) reasigns the visors to U. i dont think you lose anything with the fix, dont see what your objection to the fix is Adam, the fix has stopped alot of complaining about the bell not working.
Real SD40-2's have bells, like every other US loco as mandated by the FRA. i dont know why a bell button wasnt put in there in the first place, mustve gotten forgoten like the Dynamics
My new sounds replace the bell on both units, i got a bit lazy so both locos have a electronic bell which isnt quite accurate for a SD40-2 (better than a cow bell

) but im going to mess around with the sound files this weekend to try and create a seperate sound folder for each SD40-2 as it will be rather dull and boring if they all have the same horn.
The UP units should have a Leslie RS3-L, a PM220 (sounds pretty much the same) or a K5LA (which is what mine is)
The BNSF can have anything from a leslie S3-L, a S3K to a nathan K5LA
BN should have a leslie S3L
ATSF a Leslie S3K or possibly a Nathan P5
the IC's should have a Nathan P3.
quite a bit of variety as you can see
