Allow collapsing the commit graph commits vertically

I'm working with a big project with multiple contributors and several dozen branches. At times I need to figure out where a specific branch came from, and how it relates to the other branches, but it's hard when I'm scrolling, scrolling, scrolling to get past all the individual commits.

Suggestion: have a way of collapsing the graph display vertically, so that I can see more of the structure without scrolling. Some possibilities:

• If a range of commits are selected, then right-click to show a "Collapse" item, which collapses the commits into a single line (still showing the vertical colored lines) with a button to un-collapse

• Have a "Collapse everything" button which collapses all commits which aren't merges or branches

Another possibility: have a (floating?) "Graph Overview" window which gives you a compressed overview of the graph. Selecting items on the floating window would select them on the main window, and vice versa.