As much as I’d like to say YES! Add my vote to the feature, at least in the case of “down” I’m not sure it’ll be as much help as I initially thought.
I did a quick check to see what appears in quick add with +down and it’s already only icons (plus a few symbols I created - hidden here).
As you can see the list is rather…spacious even when it’s just “down icons.” And I’d have to scroll a bit down to find the down I might want. Only 12 of the 20 icons show at one time in that drop down while all 20 show up in the inspector view. (Don’t ask me why it has a scrollbar in the inspector! They’re all showing)
Unless I see the icon I’m looking for, I probably won’t go down through this list. It’s just too much fussing. Icon #13 might as well be not displayed - I’m never going there. (At least not with my keyboard). Example: Let’s say the icon I want is the angle-down - in the inspector I type down and then need to hit the down-arrow three times to select it. (Even for the very far “volume down” icon it’s only 7 keys to get there and I can see it right away). In the quick add scenario to get the angle-down I have to hit down 15 times to reach it and I can’t see it at all to know where it is.
So yes, you can add my vote to improving the quick add, but I don’t know how much it will help since a lot of the icons words I’d be using (down (20), arrow(25), circle(34) - are already mainly icons showing in the quick add and there are a lot in each category. I use those in the inspector all the time and I can always see all of them (although the scroll bar shows up every time even through it’s not needed).
I will say if I used less generic words it would probably be more useful icon caret(8), level(2). But if I knew I wanted the down caret I wouldn’t type in down… Then again - caret and level are already only showing icons in the quick add. But also I only have a handful of symbols that I’ve made. If I had more it might be more useful as well.