The following is tested in BIAS FX Professional but should work fine in BIAS FX2 since PG never upgrades it's MIDI implementation.

BIAS FX is the only amp sim I know of that toggles the effect regardless of the CC VALUE sent. Since MIDI 1.0 does not provide for two way communication, the only way I know of to synchronize the LEDs on the FCB with the ON/OFF status of the effect is to send the required message on preset load, and BIAS FX then toggles regardless of the VALUE, this doesn't work with the default presets in BIAS FX. However, since you would need to know what you want ON/OFF in each BFX preset anyway, I found that the best way to deal with it is to save the BFX presets with all FX OFF, then on FCB Preset Load send ONLY those CC#s corresponding with the FX you want on when the preset loads.

 

When you load the Preset in the FCB/UNO2, do it like this:

 

Preset 1 =

{   

         SendMidi DEVICE ProgChange 1
         Wait 10
         SwitchOn Stomp1

}

 

Where the Stomp messages send the CC#s for the BFX effects.

 

EFFECT_ON Stomp1 = SendMidi DEVICE CtrlChange 111 0

EFFECT_OFF Stomp1 = SendMidi DEVICE CtrlChange 111 127

 

The actual VALUES are unimportant, as BFX will toggle the FX regardless of the VALUE.

The LED on the corresponding STOMP will then be synchronized with the status of the BFX effect.
The Wait command is necessary else BIAS FX won't execute the following command.
In my configuration I have the STOMP switches in the DIRECT Bank and this works perfectly.

The VALUES above were in my AMPLITUBE configuration. Amplitube by default uses the opposite of the MIDI Standard of 127=ON;0=OFF. I then loaded my S-Gear configuration which uses the MIDI Standards, and it worked the same way.