It reduces the rocking because it is more preloaded, but there’s just not much tolerance anyway.
Just disassembled my switch again. I think the brass nubbin is to big! Mine has a diameter of 5 mm but it should be less than 2 mm with the tactile dome. Too bad I don’t have a lathe. Would be easy to create a better nubbin.
edit: Yes! A tiny blob of glue in the middle of the brass nubbin (facing towards the tactile dome) makes a huge difference! Really precise, snappy click. So all it needs is a new nubbin or literally a grain of salt at the right place. For a more permanent solution you can add a small blob of solder, but you got just one chance.