Just tried some tests of the sidechain compensation with Logic Compressor, FabFilter Pro C-2, FabFilter Pro-MB, DMG Multiplicity.
Logic Compressor and Pro-C2 are compensated perfectly. The two multibands are not. Not sure if that's a multiband problem? I was sending the kick on Audio 1 to the sidechain and auditioning the sidechain. Then removing output of Audio 1 and bouncing to line up audio. Also got different results for Pro-MB depending on if it was on an audio track or an instrument track. Weird.
Instrument track
Pro-MB 888 samples
Multiplicity 1981 samples
Audio track
Pro-MB 213 samples (early so chopping off beginning of bounce)
Multiplicity 1981 samples