Inset position and dimensions relative to the axes instead of relative to the plot

I am trying to create an inset using Plots.jl. (To be specific, I am using GR backend).

Is there a keyword argument, that will interpret bbox(x,y, w,h) in such a way that the length parameters are treated as the coordinates relative to the axes and not to the whole plot?

The whole plot includes the title and the axes labels, which are printed outside of the axes frame. Normally, you fix the font sizes, so that if the plot size is changed, than the position and the dimensions of the axes frame relative to the whole plot change, and you have to readjust the inset parameters as well.

Alternatively, is there a keyword argument to have the parameters of bbox(x,y, w,h) treated using the absolute axes coordinates?