someone please correct me if I'm wrong but from my interpretation of the source code :
debugging in: ggplotly.ggplot(ggiris, ... = "myparam")
debug: {
l <- gg2list(p, width = width, height = height, tooltip = tooltip,
dynamicTicks = dynamicTicks, layerData = layerData, originalData = originalData,
source = source, ...)
implies that the dots would be passed into gg2list.
the documentation of which -- ?gg2list implies that the dots are discarded.
... currently not used