I suspect the root cause of the following bugs is that some IMEs make the assumption that the composing region won't get committed by the editor, and the only way to commit the current text is via themselves:
On iOS you can't easily remove the composing region either (you can't move the selection to somewhere that's not in the composing region).
macOS: you can remove the composing region by left clicking some other text that's not in the composing region. But arrow key movements are still limited within the composing region.
Maybe we should make it difficult to commit the composing region, or even make it difficult to explicitly change the composing region.
I suspect the root cause of the following bugs is that some IMEs make the assumption that the composing region won't get committed by the editor, and the only way to commit the current text is via themselves:
On iOS you can't easily remove the composing region either (you can't move the selection to somewhere that's not in the composing region).
macOS: you can remove the composing region by left clicking some other text that's not in the composing region. But arrow key movements are still limited within the composing region.
Maybe we should make it difficult to commit the composing region, or even make it difficult to explicitly change the composing region.