Suppose US controls Korea and sz6. Can Japan make a combat move into sz6 including transports which, when the sz is clear, will load units from Japan and unload them on Korea for an amphibious assault?
Nope. Transports are loaded during the Combat Move phase. Since you can’t load transports if the SZ is hostile it is impossible to move them to SZ6 and load them.
A major sticking point among my friends in playing Axis and Allies is the wait time between turns.
What about having a combined purchase phase for all players?
And use markers for each IC (like fleet markers) to position purchases awaiting placement.