You know how some people, when tired of their established ways, tend to move furniture around the house to make the same thing look like something new?
Here's the same idea applied to the world of progress bars.
This is a new and improved progress bar that is making its way into R79. The idea is to use the vacant space on the right-hand side (the "todo" part) to show the sub-progress.
In comparision, here's a lively version we have now:
a GIF, trust me.
In Bvckup's case a progress bar also needs to accommodate the delta copying. In particular, the bar should be able to display processed file blocks that were copied
So here's a short list of options to achieve just that:
Will probably go either with the 2nd from the top or the 5th from the bottom. Maybe both.