In my post 18 days ago, I listed "screen with mouse" as one of the features I tested. So I guess that means it disappeared recently.
If you look at the v10.x releases, the only release that came out since that date was 10.0.2. (9 days ago)
The Update notes for KM 10.0.2 don't mention any change to this feature.
So my conclusion is that this feature changed in 10.0.2 and there was no notice of it changing. In fact if you read my post carefully, there are several other items from that menu missing now. Maybe you are the first to notice it. @peternlewis ?
I wonder what happens to any of our macro actions that were previously using those features. Are they broken now?