Pretty straightforward request; reduces clicks. If you'd like to see an example of this feature with a competitor check out FabFilter plug-ins. Most of their newer versions contain this feature whenever there's a drop-down involved and it's something that's a nice productivity enhancer.
Examples within Pigments 3 where I'd like to see this implemented (some examples, but basically anything that makes sense where this could be a benefit, there's many other spots in the synth I didn't bother pointing out in that image, as well as the other synth engines etc):
Basically, all those spots where you need to currently click, select a thing from a list, then click off of that area to proceed.
Thanks!