I've just discovered this same issue. Weirdly automating key frames at clip level was there in version 12 but was then removed.
Here's the YouTube clip explaining how it used to work
I'll give an example of why it matters so much to be able to do this record automation on the keyframes at clip level – as with Avid, Premiere and FCPX. Recently we worked on a feature length film that went to several film festivals WHILE the edit was still live and we were still editing the running time down. So we did the first sound mix for London Film Festival, and then removed a further 8 minutes by the time we premiered at SxSW a few months later, and we had removed another 4 minutes by the time HotDocs Toronto came around.
Each time we fine-tuned our edit, we retained the sound mix from the previous pass, but with Fairlight's track level automation, this would mean that any time we tightened an edit, or removed a sequence altogether, the track level changes would now apply to a completely different sequence, and the sound mix work would be destroyed. A single edit on any production will destroy the track-level automation mix.
So for us, this would have meant doing a completely new mix, while we were racing against the clock to get the master finished to screen to a full theatre audience. Every second counts in that situation, and a full new mix would have taken a couple of days to be ready for an audience.
If DaVinci is to be a serious professional tool, then it needs to reflect the real situations that we run up against.