This has been tested on Exchange 2010 SP2 ru7 to Exchange 2013 cu11, and also Office 365 cloud cutover migrations that sit stalled for hours/days on “Completing”
Jobs are stuck in RelinquishedWlmStalled or Reliquished status
I had to deal with this issue today with migrations from e2010 to E2013cu11. after messing around all day with MRS values and restarting, the one thing that liberated the jobs was Set-MoveRequest samaccountname -priority emergency
that sent them through within an hour after sitting idle for 12+ hours!
I only did 2-4 at a time though, don’t overload MRSproxy service.