> As suggested in the subject line.
> It seems it is not and I have been `C-x p k' then `C-x p o' to close and
> re-open a project, which is cumbersome.
It may not be easy; project_opened() in config.py should be called only
when opening the project and some of the configs have no effect when
set later, like extension_modules. So I suggest simply writing a
lisp function that calls these two functions and binding it to
something like "C-x p r".