It would greatly enhance the UI to have the sidebar retain its size, i.e. if I drag it to make it wider to fit my collection names comfortably, it should ideally retain and restore that size.

It would also be extremely useful to have the ability to close all active tabs at once. I sometimes have multiple tabs open. As a workaround, I exit Compass and restart it without having to close each individual tab. But then the sidebar issue comes at play.