I don't know is this is already a thing, but I came across the following problem when designing a logo:
the logo has a part that looks like this:
As the background of the shield is always white, I fixed this by grouping the black curves and applied a white outline to it.
the problem is that this will rasterize when exporting to a vector format like svg or eps. So I wanted to counter this by creating a substract compound with the green and grey shape beneath it.
I tried to select the group and expand it using Layer -> expand curve, but that didn't do much.
I solved it by manually copying the curves, enlarge them to the right size, expand each curve as creating compounds will not take curve thickness into account, and then create the compound.
The problem I encountered then is the fact that enlarging the curve thickness is not always the same as outlining, so I had to manually transform some points to match the outline.
Is expanding a group of curves with an outline a feature in designer? Or is it on the horizon? It would save a lot of times to solve problems like this.