In the old version I was able to type search through categories using a text box above the category list. As I was typing the list was filtered. This functionality seems to have gone. As I have quite a few categories and use this functionality every time I use Press This, I was wondering if it could come back.

Root cause: The Gutenberg modernization (354ccf3) replaced the old jQuery-based UI with a React component but did not port the category search/filter input that existed in assets/press-this.js (lines 842–863). The old code used a .categories-search keyup handler to filter a cached list of category DOM nodes; the new PressThisEditor.js rendered a flat checkbox list with no search input.