Let's consider a package, which has been released by a user to a volatile index, and later pushed to a non-volatile index. The push operation could happen multiple times between a few indices. In the meanwhile, the package on the volatile index could have been modified.
When searching for that package, often the very first search results point to the one in the volatile index.
It would be nice if the search could be customized. If it isn't possible, perhaps packages from non-volatile indices should be displayed on the top of search results by default.