Much like the “All” section of the file switcher, the Home screen can suffer from performance loss when there are many files on the workspace. It shouldn’t matter how big a workspace is, the Home screen should always be fast and render quickly. Another point to consider is that when there are many workspaces, opening a multi-model workspace that is all the way to the bottom of the scroll will open a drawer panel to the right side completely empty; that happens because the models are listed at the top of the drawer panel. This is pretty confusing and doesn’t make for a good UX. 

Replace default list of PatternFly with https://github.com/bvaughn/react-window or https://github.com/bvaughn/react-virtualized.