Only visual notes.
1. Long names do not fit, i.e. there is no wrapping or tooltip.
2. Overlaying icons on top of text, i.e. in addition to the first point.
3. There are options to think about the UI of an empty field with alternative search filters (alphabet, author). For example, add sorting items alphabetically and in reverse order, or write "all". Ideally, change the layout of the elements.
4. It is interesting to search for a single character. Does it make sense or limit the minimum number of characters? It might be worth dividing it into heading searches and description searches.
5. In addition to the previous point. We see descriptions without localization (at least filter names), and viewing these descriptions is not displayed in the standard view (without search). Surprise - hidden text.
6. Find a description. Select a filter. Search again. For the duration of the search, we see the icon of the selected filter, the rest disappears.
7. Something seems to break when displaying a large amount of text in the right margin. Look at the strange text for the last item "Invert around primary color". When searching for "Invert around primary color" or searching for "Maximilian" we don't see this glitch.
8. Sorry. I did not immediately understand that the search works immediately with the catalog on the site. The information above may be slightly inaccurate. Here somehow it is necessary to designate the place of the search or do the search filter for local plugins separately.
9. If possible, then from the description found in the directory, determine installed plugins. For example, to show the plugin icon to the left of the name (in the description). Clicking on the icon highlights (framed/colored) the installed plugin in the left column.
10. "Question" (?) in the window title refers to the main topic. I do not know if it is necessary to change the link to the code for the test version.