コンポーザーがヘッダーを上にドラッグしすぎると、ヘッダーの下にスタックします

No it hasn’t - it is still very possible to get the composer stuck under the header on Chrome (on a Chromebook) on my machine.

However, the recent improvements to the fullscreen composer have removed the need to drag the composer up high:

「いいね!」 1