Duplicate constraint and add constraint from source

Hi awesome Devs.

When rigging face, I often use the action constraint. It's a pretty long and repetitive constraint to setup. And often, on the same bone, I need to add twice exactly the same constraint but with 2 different target. For example, a bone on the middle of the mouth that can be triggered by both left and right controler with a 0.5 influence each.

That would be awesome if, as for modifiers, we have the possibility to duplicate a constraint with a drop down menu. So that, I would have exactly the same constraint setup and would only have to change the target.

The second thing that would be interesting (at least for me) is, when using the "Copy constraint to slected bone" command, to be able whether to replace all constraint of the selected bones by the active one as it is right now OR to be able to add active bone constraint to selected bones.

For example, bone A has an IK constraint. Bone B a copy loc constraint. I copy constraint from bone B to bone A, A lose its IK constraint and get the same copy loc constraint as B. Would be awesome to have the choice to keep original constraint selected bone and add new ones on top, or keep the current behavior of this command. Hope it makes sense.

Regards, Pierrick