..... much along the lines of the system now in place in Russia, where the 'pre-processing' is done by couriers and mostly now no interview required.
I think you misunderstand the system in place in Russia, and indeed in place in an expanding list of other countries.
In Russia the outsourcing company, VFS, to not make the decision about whether the visa should be granted or not. That task is still clearly in the hands of the staff at the British Embassy/Consulate.
All VFS do is an initial check, to ensure that all the correct supporting documents are in place and then transmit the application etc on to the British staff for a decision.
Ukraine? There is nothing on the website of the British Embassy, Kiev, website about an outsourcing arrangement. However there is now the ability to make an application online. Hopefully an arrangement with an outsourcing company such as VFS will follow in due course.