Top 3 best ideas in amiga history?

[AeroMan]

Draggable screens.... Oh man, how I miss them

[AeroMan]

Actually, that's not entirely true. The screen behind was "mode promoted" to whatever the front screen was running at. If you partially revealed a 31kHz mode behind a 15kHz one, the rear screen would appear stretched on the display until it was brought to the front. Only one scanrate was used for the entire display at any one time. Trying to change rate mid-frame would not do a CRT any good at all.

That´s true only in 31kHz. If you are using a 1084 for example, and you have a hires and a lores mode they are running at different pixel clocks. As long as you keep the sync signal at the same rate, you can change resolution without promoting modes