The QGIS Style Manager dialog (which allows users to setup and manage their own libraries of symbols and color ramps) now opens non-modally, so it can now be used alongside the main QGIS window (just like the Layout Manager dialog and Print Layout Designer windows).
We've also improved the preview of symbols within the Layer Styling dock, adding a toggle to switch between a large icon view and a detailed list view of symbols. Hovering over symbols (and colors!) now shows a large preview of the symbol. Finally, we've made symbol lists more hi-dpi friendly.