really depends on the tune with sidechain
most of the time its just the kick doing the heavy sidechaining, snare doesnt really need an aggressive sidechain, since theres not much low end to a snare, but it can help with overall mix, so i may sidechain that at like half the intensive of the kick sidechain. i use shaperbox to side chain tho, and you can have that set to 3 bands low/mid/high, so low is fully ducking, mid is half that, and highs are half that again, that way you still keep the overall sound your ducking, but still ducking aggressive, but you dont really hear it, not like a blank cut of audio.
main reason i use a synth kick/click, is the transient is small, DnB is fast, so you need a quick sidechain trigger, a big fabby kick controlling sidechain, can be too long. its trial and error, 9/10 it works tho, you can even use whitenoise to sidechain, since its just a block of sound