On the 747 Classics that didn't have the half flow option, we used to shut down one aircon pack as normal ops in cruise (and close the heat exchanger air inlet door for that pack), and restart it just prior to descent...never a problem!
For those that are not aware, the 747 Classic had three packs and a flight engineer to operate all these fiddly bits, all very good things to have!
Flew them for years that way...
Cheers...FD...
