I just learned that another team at my job has a project of a similar size to me and their reload CMake using all four configuration types takes 12 seconds to run, while my project takes nearly two minutes when running all four configuration types.
I recently learned the trick to change the configuration types (Thanks Anna Filipova!) so that helps.
But even so, it seems if there is a fundamental problem with my project. We are sharing most of the CMake include files and the project only differs pretty much at the top level CMakeLists file. We also share most of the libraries.
Is there a way to examine the complexity of the built indexes or cmake behavior?