One sign of corridor maturity is that return-leg drift is no longer discussed only in the language of failure.
Fleet operators are increasingly modeling it as a routine cost category with direct implications for maintenance, reacquisition planning, and downstream scheduling. That does not mean drift is harmless. It means the industry has stopped pretending that favorable-direction transit can define the economics of the whole stack.
This shift matters because pricing changes behavior. Once return drift is treated as a normal planning burden, operators get more honest about which vehicle classes to use, how much margin to preserve, and when a route should be declined altogether. Markets often become more credible the moment they stop hiding their asymmetries.