I don't really understand what "pancake timeline" is. Can it be done in CinGG?
Maybe you can do a workaround that mimics the timeline pancake.
Two instances of CinGG start: the first collects all the sources queued in its timeline. All windows except the timeline and viewer are closed. The second instance will host our editing as we choose the clips from the first timeline and copy them to the second. Of this second instance we leave only its timeline and the compositor window. The only difference is that you have to use keyboard shortcuts for cut and copy, instead of being able to do everything with the mouse.
It doesn't make your system too heavy because CinGG boots very fast and is fast until you use too many effects in the second instance.