cc @bokeh/dev thoughts on the arrow sense? I understand why they are why they are but it was contrary to my expectations. I.e. in order to "pan left" you have to "drag right" and I expected the buttons to indicate the "drag" direction, not "pan" direction.

Yes, it was a bit counter-intuitive to me.

This behavior is consistent with arrow key function in google maps, leaflet and other. Left arrow reveals more of what's on the left of the plot. Pan gesture that achieves the same function is drag to the right. Perhaps it would have been more clear if I used a map based example, e.g.:

This behavior is consistent with arrow key function

Well that's actually interesting, I would expect the behavior exactly as shown WASD or arrow keys. I think the difference for me comes down to mouse vs. keyboard, where using the mouse to click the arrows just really suggests the operation is analogous to a drag, also with the mouse. i.e. click a right arrow with a mouse ~ move to the right with a mouse (i.e. "pan left")

I won't hold up the PR but I would like to know if the eventual plan is that keyboard navigation will work without having the toolbar icons present at all? Frankly, adding four icons to the toolbar is "alot", especially if there are even a few other usual tools present. I can't actually imagine that users will truly want these cluttering the toolbar in most cases.

I won't hold up the PR but I would like to know if the eventual plan is that keyboard navigation will work without having the toolbar icons present at all? Frankly, adding four icons to the toolbar is "alot", especially if there are even a few other usual tools present. I can't actually imagine that users will truly want these cluttering the toolbar in most cases.

The next step will be to add keyboard support, but that's quite a bit of work because we have to add focus management for plots (so that arrow keys only work when plots are in focus) and coordinate key handling with other tools.

I don't expect users to add all four buttons a toolbar like in the examples. I would expect they would use buttons like that when their plots pan only in one direction (equivalent to e.g. PanTool(dimensions="width")). Whereas if they need both dimensions, then they would arrange buttons in a cross layout within the frame area, though that will require further work to allow full customization of tool buttons and related controls, and their positioning (so something that goes beyond what PR #13571 tries to achieve).