To avoid cluttering the examples with tons of code to produce nice plots, I think it would make sense to provide a few plot functions taking directly an OptimizeResult object.

See e.g. the plot_acquisition and plot_convergence functions in GPyOpt (at the end of http://diana-hep.org/carl/notebooks/Parameterized%20inference%20with%20nuisance%20parameters.html)