Colour Toning (multiple instances) + History: Bug or by design?

The Colour Toning module allows for multiple instances, but those can’t be turned on/off individually. Only the module as a whole can be turned on/off. There is a workaround, but I’m wondering if I ran into a bug or that this is by design.

The workaround: All actions are shown in the history window and you can select any step and all is reverted to that step. Once you have seen the before, you can go back and select the last step and you can continue working.

But: The thing that is not activated correctly is the instance that you came from. It always reverts to the first (top) one. All the edits are still present for all the instances, it is just that the focus isn’t on the correct one and this makes for a bit of a surprise when you continue editing (on the wrong instance).

QUESTION: Is this by design or should I make a bug report for this one?

And, addressing the underlying issue: Would a feature request to turn the individual instances on/off possible be seen as useful?

Here’s a really quick and dirty video showing the above behaviour: