?
That value is in seconds. For the performance aspect, it should be relatively fast with your number of packages. Do you by chance have a wildcard connector filter configured for the feed? That is what typically adds the most time to package requests, as the requests to the connected NuGet feed end up using the OData "startswith()" function which is not the most efficient.
Otherwise, if you don't have a connector filter and are experiencing slow downloads, once the new indexing method is implemented (scheduled for v3.3), the delays should go away completely and you shouldn't have to restart the service. As implemented now, there is a FileSystemWatcher that monitors the entire package directory, which can do strange things with lots of files, especially when the packages are stored on network shares. In the new version, it will monitor only an empty drop folder, and once packages are put in it, move them into a subdirectory format like "/package/{version}/{.nupkg-file}".
We are beginning development on this feature starting today now that our v4.5 of BuildMaster has been released, so keep an eye out for the next minor release. Note we may actually add this feature to a maintenance release of v3.2 without formally announcing it, so check the release notes to see if it's included.