I am not sure how the option "... also when zooming" in replay viewer is supposed to work. Currently, when using "Follow driver" option and zooming with mouse wheel, the driver is followed if the replay is playing and is not followed when the replay is paused. The option "... also when zooming" seems to not have any effect in either of these cases.
Same goes for the button "Click and hold to zoom in/out". It follows the driver when replay is playing (this might just be a coincidence as the driver is in the middle of the screen anyway) and does not follow the driver when replay is paused, irregardless of the "... also when zooming" option.