Now that there are diverse stances, the current all-or-nothing digital leaning seems a little bit out of place.

Therefore, it would be nice if there is a lean bind similar to 'Look' bind, in which you hold down the bind and move the mouse to control the leaning status.
The bind should reset the leaning status whenever it is pressed. Or, alternatively, there should be an separate bind that resets the leaning status.

An another possibility is 'Continuous Lean Right/Left' binds, where you hold down one of them until your character's leaning status is ideal, and let go of it to stop the leaning process.

The first solution is better than the second one, in that you can adjust the leaning status more precisely. It also requires just one or two binds to be used, while the second solution requires two main binds + 'Reset Lean Status' bind.
However, the second solution is better, in that you can aim while you are leaning.
I personally prefer the first one, but ideally, both methods should be implemented, to allow diverse configurations.