Sometimes I want to select only several items from a kit. If my inventory is full, or if the kit contains lots of items, the kit won't be redeemed and I have to do nasty inventory management.

I suggest implementing a new command such as /kitc mykit or option such as /kit mykit container. When the player runs this, instead of simply attempting to add the items to their inventory, it will open a container which they can selectively loot. When closing the container, a bag will drop on the ground with the remaining items. Alternatively, the remaining items could be deleted, which could be possibly configurable at the plugin level.

I can implement this as a pull request if you put this plugin on GitHub.