The existing text-based geom layers in ggplot2 (geom_text and geom_label) are ideal for the majority of plots, since typically textual annotations are short, straight and in line with the axes.
When I use ggplot2::scale_y_continuous(sec.axis = ggplot2::sec_axis(~ . / scale_factor)) like this, I discovered that plotly does not support this function. Providing support for this function would ...