Changing input scheme in-game / during gameplay?

I have searched through the questions and mostly only find how to change the controls for the game in the project settings. I am aware of Action and Axis mappings and can use them effectively. My issue is that I cannot find a way to re-map those Action and Axis mappings during gameplay, only in the Editor.

This is a standard operation in many video games, for example: remapping “movement” from WASD to IJKL, remapping “the inventory menu” from I to C or remapping “Jump” from Spacebar to E.

This is usually something available in an options menu. I would like to provide this functionality, but I do not know the best way to approach it with Unreal Engine 4.
My assumption right now is manually handling it using the BindKey function in my own class, but this seems like something that could be available in Blueprints, instead?

With a bit of exploration, I feel I have found an adequate solution to this problem, and it was as I expected.
I created an “InputMaster”, derived from PlayerController. This class then held a map of strings (the names of the actions) mapping to FKeys, which could be edited through a menu. The map is defined by default, but editable.
When the controls are edited the class would handle binding the new FKey to the Action.
Unfortunately using BindKey doesn’t seem to have a way to Unbind that (very strange?), so now the question is:

After binding a delegate to a key in C++, can you then Unbind that key?