This is one of those weird questions I would expect to be documented (Especially on Tech Net), but I honestly haven't found an actual explanation. As of Server 2012 R2 you can set your cluster nodes to drain on shutdown. However, as is the case sometimes, the drain procedure will not actually succeed. At such a time, it seems like the server will hang on this procedure for a long time.
What I want to know is, what is the maximum timer the server will attempt to drain all roles for, and is there any way to change this timer?