I've tried several times to do this through calibration tab and it doesn't work at all.
This is my calibration tab:
https://imgur.com/QmrvMbg
and this is how setting throttles to minimum looks in the sim:
https://imgur.com/QIwPBCq
INI sections for this plane below. I've tried to see if there is any difference if I set one axis as "Send to FS as normal axis" and the other as "Send direct to FSUIPC Calibration".
There is no difference in behaviour in sim.
[Axes.BAe146]
RangeRepeatRate=10
0=BR,256,F,66382,0,0,0,*-1 -{ TO SIM: AXIS_SPOILER_SET }-
1=BU,1,F,67103,67110,0,0,*-1 -{ TO SIM: THROTTLE1_AXIS_SET_EX1, THROTTLE2_AXIS_SET_EX1 }-
2=BV,1,D,11,12,0,0,*-1 -{ DIRECT: Throttle3, Throttle4 }-
[JoystickCalibration.BAe146]
AllowSuppressForPFCquad=Yes
ExcludeThrottleSet=Yes
ExcludeMixtureSet=Yes
ExcludePropPitchSet=Yes
SepRevsJetsOnly=No
ApplyHeloTrim=No
UseAxisControlsForNRZ=No
FlapsSetControl=0
FlapDetents=No
ReverserControl=66292
Reverser1Control=66422
Reverser2Control=66425
Reverser3Control=66428
Reverser4Control=66431
MaxThrottleForReverser=256
AileronTrimControl=66731
RudderTrimControl=66732
CowlFlaps1Control=66162
CowlFlaps2Control=66163
CowlFlaps3Control=66164
CowlFlaps4Control=66165
SteeringTillerControl=0
MaxSteerSpeed=60
RudderBlendLowest=1
Spoilers=-16264,-13220,16133,16264/16
Flaps=-16248,16220
Throttle1=-12594,-12490,-12364,16383/32
Throttle2=-12471,12596,12596,16383/32
Throttle3=-12593,-512,512,16383/32
Throttle4=-12594,-512,512,16383/32
Thank you.