Two curves, two individual y-axis/y-ranges but one zoom/pan action

I successfully set up a bokeh line chart with two separate curves, say A and B.
Each curve has it’s own associated y-range.
Curve A uses the default (figure.y_range) curve B uses a different (extra_y_ranges) with different scaling (of course).

Now, when I select the mouse scroll zoom tool or the drag tool and put the mouse over one of those y-axis,
I would expect _only_the associated_curve to react to the action (scroll-zoom, drag ).
But instead both curves and both ranges/axis react to the zoom or drag.

It is clear, that there is no simple distinction possible when I use the mouse pointer within the chart.
But having it hovering over the axis/scale I would expect separated actions on either curve not both.

I there a generic way to “unlink” the curve-interaction?
(Did I miss something?)

TIA Thomas

The same issue is asked on stackoverflow with no apparent answer for 6 weeks.
Could someone confirm that it’s impossible?

This would help to move on.

Thomas (again)

P.S. wasn’t me on stackoverflow ;^)

It’s not possible, twin axes are always linked, and scale together relative to their initial range start/end. I have answered on SO as well.

Where do I have to look into the code, in order to (try to) understand how the axes and (extra_)y_ranges work together and how the interactive scaling interacts with them?