This setting defines the number of seconds NCrunch will wait during initialisation for the IDE to provide the details of all loaded projects.
NCrunch will always cross-check the number of provided projects with the contents of the solution (.sln) file. This means that the engine is usually aware of which projects still need to be loaded, and the timeout delay is not used as it is not necessary. Thus this configuration setting exists only to give fine control over the engine in certain edge cases.
Under normal operation, there should be no need to change this setting.
Because projects are loaded asynchronously by Visual Studio, and can be loaded/unloaded at any time, the mechanics of VS integration can introduce edge cases where NCrunch expects Visual Studio to report data for projects that are actually unavailable or unsupported in the IDE. To prevent the engine from stalling, NCrunch relies on a timeout after which all projects are considered to be reported.
If you are working in a solution where NCrunch is relying on this timeout because of unloaded or unsupported projects, it can be beneficial to reduce it from its default of 60 seconds to reduce your overall initialisation time.