I may be lost but I don’t think you can approximate parallel compression with a transient shaper. The reason is, well, you are dealing with peak levels where compression deals more with rms/average levels. For me, transient shapers are a utility for standing something out or back and I don’t use them much. Sonnox transmod is awesome and cubase’s transient shaper is very hit or miss. Anyway, compressors work so differently and they bring up the body of a sound when you use them certain ways, or create pumping effects, and other… which is typical in a parallel compression technique. I will aux into a transient shaper and keep the original untouched for more snap or whatever I am after, but this is not parallel compression. This is parallel processing though, not parallel compression.
Could you use a transient shaper to soften the transients which would allow the underside body of a sound to become more present, yeah, but I wouldn’t call it an approximation of compression because it is not compression.
It’s always a science project getting everything to exist in harmony within 20-20kHz. Then you have width, elevation and depth too. Itsah-3d-environment
Bla bla bla arrrrrrrrrr!