Please note that SortSpec is available in the 0.20_xx devel branch of KinoSearch but not the stable 0.1x branch. While you should be able to use the devel branch on systems that you control, submitting a patch for SVN::Log::Index would be problematic: unfortunately, adding features such as SortSpec to KS necessitated changing both the file format and the API in ways that are not backwards compatible.
When the KS devel branch approaches release maturity, I'm willing to work in conjunction with CPAN authors who have distros with KinoSearch as a dependency to update their modules. Patching for the current devel release probably wouldn't make sense though, because the KS file format and API are still unstable. (As for release schedule, I never issue time estimates unless somebody's paying me :) -- but FWIW I am working on KS full time right now.)