I am not sure if this question has been asked or answered. But does the vst3 in X3 support sidechaining? Was trying to sidechain my waves plugins and not finding there inputs.

CA-2A is VST3 and supports sidechain.
Cheers...

Yes I can find the inputs for it but not my waves plugins

So are the waves plugins supposed to support side chaining in the documentation or the specs?
You will probably need to look at each one specifically.

It would depend on the plug-in but those that support sidechain should show up in the track output/send drop downs of other tracks.

Pretty sure the RenComp has sidechaining at least.

Did more looking seems to only be an issue with waves C1 comp-sc the others including RenComp seem to work. Seems to be an issue on the waves side.

Sonar totally supports the Waves sidechaining in VST3 as I am using it on many including Vocal Rider.   YOu need to make sure you have your VST3 plugs properly installed.  Makesure you have the waveshell vst3 in your plugin installation path etc.    Also there is a setting in the plugin manager  or in the preferences which tells Sonar to use the VST3 when they are found.  I wouldn't go to Waves as your issue is likely in your Sonar setup.   When properly installed, ALL the waves plugins show up as VST3, not just the ones that use sidechaining.  That said, all the plugs that are supposed to sidechain work for me as I have one of the larger Waves bundles.    Keep working at your waves/ Sonar plugin setup / installation and you willfigure it out

Also beware that the sidechain input may not be named exactly as you would have expected it.