Generalizing supererogation

My preferred way of understanding supererogation is that an action is supererogatory provided that it is permissible and more burdensome than some permissible alternative (see here for a defense). This suggests an interesting generalization. Let J denote an individual or a group (perhaps described relative to the agent). Then an action is J-supererogatory provided that it is is permissible and more burdensome for J than some permissible alternative.

Then supererogatory actions are, in the new terminology, agent-supererogatory. On the other hand, we have a new category of actions, others-supererogatory. These actions are permissible but more burdensome to others than some permissible alternative. An action can be both agent-supererogatory and others-supererogatory. For instance, suppose that by sacrificing two arms I can save two people from losing two arms each, but by sacrificing one arm I can save one person from losing one arm. And suppose I have no special duties here, so it is permissible for me to make no sacrifice at all. Then, the action of sacrificing one arm is agent-supererogatory (it is more burdensome than the permissible alternative of no sacrifice) and others-supererogatory (it is less burdensome than sacrificing both arms).