I use graph-tool to do some routing tasks over graphs ranging from 1M to
10M edges. To search shortest paths might be quite time consuming. Hence, I
wonder if it might be a good idea to try to implement Hierarchical
Contractions [1] in graph tool.
This sounds useful; I have nothing against implementing it. However,
time is always limited. If you want to help, you can open an issue for
it in the website, together with a link to the algorithm, existing
implementations, etc. This would help me getting around to it when time
permits.