What a shambles! I’m happy with the old site so if they keep it going that suits me and probably many others, but it makes you wonder how they made such a mess of this expensive upgrade.
Mine will idle down to about 1450, but I don't go below 1800 unless stopping the motor. It also helps to cut one magneto at about 1800 and wait two or three seconds as the motor slows before cutting the other one. It stops with less of a clunk. A 2000 rpm idle is a bit slow when the engine is cold. I usually run it a 2200-2300 initially.
Yes there are areas that are non critical where it wouldn’t matter, but why mix and match rivets. They are not exactly expensive and it’s just not good practice. However your plane, your choice.