Yes, individual modules can be placed back into the original box in the configuration that they arrived in for longer term storage. This includes modules that are originally packaged upside-down.
However, all individual modules that are packaged inside each box are designed to be free-standing and can therefore be stored separately in fridges or freezers in an upright position. This is the safest option to avoid any potential volume loss over longer-term storage.
ATTENTION! If storing tubes back in the original upside-down configuration it is critical that all tubes are tightly sealed! We recommend spinning down all reagent tubes thoroughly before opening (both before and after thawing).