Not too keen about borderless buttons, the following looks odd
The following may have been so in earlier releases.
Up/down arrow keys don't work in Tag Browser Find box, I end up traversing the book list search box history.
The keyboard shortcut names 'Find Button' and 'Find Item' don't make sense, to me at least. 'Find Item' clicks the find button or takes you into the find box if it's already open, and 'Find Button' selects next match. I suggest they be relabelled to 'Select Next Match' and 'Tag Browser Find' respectively.
And I would relabel the 'Alter Tag Browser' kb short to 'Change Tag Browser', so that it matches the tooltip. Alter is something you do to clothes
BR