Ability to fully retract bottom screen lines that are recently added
Lines written at the bottom of the terminal push all other lines up, and upper screen lines go into the terminal program's history. AFAIK there is no standard ability to retract the bottom-screen added lines and bring back the top lines from the history (or there is? CSI 'scroll up' only adds empty lines at the top).
Way in which the extension is useful: today's very common terminal programs such as fzf, along with tab completion features of shells, take a few lines from the bottom of the screen in order to present the user with options to pick from. However when the completion mode ends, empty lines remain. I'd like the standard to be extended to allow for the 'unwinding' of the empty lines.