The downloadable plugin Create Insert Symbol Plugin plugin (category Other) has been update to add a Find Symbol In List button to make it easier to find the one you want.
I had noticed a post where it was mentioned that it was hard to find a symbol, and I was wondering if a Find button in that dialog would help (like Find In Ribbon).
The disadvantage is that you would need to know at least the approximate name of the symbol because you could not type in a symbol itself.
Rather than asking for the feature and waiting to see if it might work, I updated my Create Insert Symbol Plugin plugin, which uses a list of symbol names, so you could type in any part of a symbol name, and you could get a list of symbols that included that text (case-insensitive).
If anyone feels like trying it out, please let me know what you think. I personally think it saves a lot of effort, and it would be nice to have in the Symbol gallery and dialog.
As long as I am thinking about this, I also think that File > Open would be a lot more useful if the string you typed in matched anywhere in the file name, not just at the start, as it does now. MuseScore does it that way, for example, and I find it very useful for when you only remember a part of a name, which might not be at the start.
Just thought I would mention that a plugin cannot display graphics (though Sib itself could), otherwise I would show the actual symbol in the list along with the name.