It occurred to me that a simple way to configure the inline backend, in particular to choose between standard PNG, retina (2x) PNG and SVG (and future PDF?) would be via the following syntax:

%matplotlib inline svg

or

%matplotlib inline --svg

I had a look at the code, but I don't know enough about how either the command-line argument parsers work, or how the configuration works, to implement this.

In this way, there would be no need to make the %config InlineBackend stuff so public.