I'm afraid none of this is possible at the moment. To be honest the whole multiple items thing was a bit of a dead-end for me. I coded it like that because I thought, for example, having a supply box with different gift shop items could work, but then I realised that the more modular you make things, the better control the player has, so I never actually used the feature.

Hmm, interesting choice. But I think I get where you're coming from.