Oops, you're right - I meant we generally strongly recommend it on the forum. (The tutorial should probably be updated to reflect that.) Because 'set position' requires a teleport and it's difficult for the engine to keep up with this, it has a tendency to make physics games unstable in general, not only just in this specific example. So we recommend using physics forces for everything and avoiding set position/set angle altogether. While I've implemented a workaround along the lines of what you described, it will not prevent you having other problems based on 'set position'.