In v5, The sidechained result now rendered correctly to the bounced replacement events. But when you transform back to realtime, the original compressor (or ducking VST) is restored to the track's channel inserts, but the original sidechain routing is NOT restored. You have to remember what the original sidechain source was, and manually set up the sidechain routing all over again.
Interestingly, though, any Sends that exist have a different issue. When you transform to audio, the Send is removed entirely, so you lose the original processing through any FX tracks. But at least when you transform back to real-time, you get the Sends back.
Also interesting is that any channel notes you've written are lost during a transform and re-transform back.
So..... some small progress, but still far short of how it should behave.