Sylvia Massy uses the Avid BF-76, a 1176 emulation originally released by Bomb Factory, as a parallel compressor to add weight and punch to the kick and snare.
The parallel path is called "Spank" and is part of her template.
The compressor attack is set to longest, release to shortest, ratio is 4:1, gain reduction averages around 4-7dB. This approach enhances their transients, making them more prominent and pushing them to the forefront of the mix.
Note: Massey is using the term "sidechain" instead of parallel compression. Typically this refers to compression triggered by a separate key input, which is not the case here.