TMFX v 1.93 MacOS (3)
RME Thunderbolt Settings Firmware: v112, Driver: v1.05
Fireface UFX+ (23919669) (the old hardware version, I guess: SW Version: 55, Active Nodes: 105
Mac OSX 12.7.2 (Monterey)

The range of the threshold knob in TotalMix FX goes from -99 dB to -20 dB.
The value range from OSC goes from 0 to 1: but this only maps from -99 dB to -30 dB.
Anything above -30 dB has a value above 1.
TotalMix FX does not react to values above 1.
This means you cannot save all states of the expander threshold with OSC data.

I consider this to be a serious bug.

Best regards,

Arthur Sauer