This depends on how you might model the 'owner' / 'utilizer' to which the cost would ave to be assigned.Are you using goods movements to move the equis around?
No guarantee - but usually the code line between ECC and S/4HANA Private cloud concerning such SAPGUI transaction is as far in sync that existing official extension points are available also in S4CORE.In S4core additional/new checks might kick in.
IMHO teh aspects of mass changing Company code and Plant are completely unrelated to the question relating to alternative labelling (AL) for functional locations (FL).Please check corresponding doc and notes for AL.When activating it newly created FL...