If the thread (solid Helix) end needs a run-out I Extrude the end face of the solid>Helix approximately the radius of the threaded shaft. That will normally give a good (visual) lead-out and means you only have the one Boolean (Subtract/Remove) to do. https://cad.onshape.com/...
Since you’re using a fresh install of Windows 11, the first thing you’ll need to do is install the latest updates for Windows 11 from Microsoft. To do this, go to the WindowsStart Menu > Settings > System > Windows Updatewhich is in the bottom left hand corner. Windows 11 may prom...