Hey A&H Team,
little idea for better workflow with the Peaklimiter76:
You could make the dedicated “Comp Threshold” Encoder turning the Input and Output Parameter simultaneously. Output has to go 1dB down, when Input is 1dB raised. Like there’s an inverted rubber band between the two knobs. 
If one like to change just a single parameter, you would use Display + Touch and Turn knob as usual.
Cheers, Alex