Thank you - is there a way to redraw the envelope in bulk? I tried selecting the area and moving the envelope but it doesn't do anything. Seems I can only move one point at a time. I'm used to effortless DAW edits, it's so clunky in Vegas...

If it is like the other envelopes in VP, you can select a region or use the envelope edit tool., But as I stated, I have yet used the new 'ducking' tool and I do not know if those envelopes work the same.
FWIW, I always preferred a side-chain compressor,.. which Vegas does not support, despite requests going back to the original audio-only Vegas 1.

Always found it incredibly effortless to be able to drag-select a region and insert 4 envelope break-points with one click using the normal edit tool. Then drag the middle pair together to a new level... just odd that the envelope edit tool won't do it. And limiting that neither tool lets you choose other arbitrary points you want to move or set together.

FWIW, the ducking control envelope shares all the same editing capabilities and limitations of Vegas envelopes generally. Including the ability to copy and paste the points to a different kind of envelope on a different track. I did beat my head against the wall for a bit trying to make the feature work for me and found I could duplicate a track, insert a volume envelope, then paste in the points from a control envelope. And if I selected regions carefully, could achieve an offset on the paste to effectively slide them in time. Just an awful lot of work to make up for edit limitations and lack of delay, offset, and slewing-rate controls which are kind of important to ducker functionality. But I found it easier to just draw in my volume envelopes manually from scratch and do overall peak-level tweaking with other envelopes, like compressor input or output gain, or another volume envelope on a bus.