Sidechain to compress & expand?

I am just learning about sidechaining and ducking, reading about dynamics compressor/expanders
And, a question I have, do audio engineers ever compress to duck one channel and expand the other?
Thanks for sharing.

You canˋt expand with a compressor. Or do you mean use one sidechain signal.for sidechain compressing and expanding to different signal?

there are compressors that can also work als expanders. but your question is valid, what does the OP mean?

Then you I suppose, you can switch between compressor and expander module? Acompressor as per definition does not do expansion.

yes I do mean with side chains from different signal or even signals. I don’t know it these plugs can take multi in to side chains but you could always use a group channel and was just reading about Meldas Dynamic EQs that can either compress or expand per instance, and I guess fab makes one that can do either in same instance - thanks
I also think what I am thinking is sidechaining to and from each other - don’t know if it even can be done but conceptually - fer example simply using the side chain to duck instruments for the voice, and side chain to expand the vox over the instruments. I haven’t tried to set it up yet… the concept seems like you wouldn’t have to do either as much as with just one sidechain… don’t know just a thought.

What I was describing is implemented in compressors for audio engineers to use, just discovered.