Drawing the plot of a curve with the handy "plot a curve" utility I discovered that the plot cannot be edited in the current version (2018a) while it can in 2016d, which out of laziness I have still installed at home.I can confirm that on almost-current git in the context menu of such a plot I don't see an entry "edit". Is that what you mean? I don't know how it used to be in older versions.