If I am not wrong, that is a possibility for other commands (e.g. sdist, bdist_wheel, etc …) but not for the install command.
I think effectively extending install is deprecated because the logic to install packages now belongs to pip (and python setup.py install should not be used).
Unless, of course, you are using some shenanigans to customize how bdist_whell organize the file structure of the final zip archive. In that case, this is not supported yet by how setuptools handles --config-settings and the workaround would be something similar to what Miro described.