ALE currently supports numerical features only. An extension to categorical features is possible, but comes with serious caveats for interpretability (see https://compstat-lmu.github.io/iml_methods_limitations/ale-misc.html) so I think some more research needs to be done before investing in categorical feature support.
Tagged as low priority as it is unclear how to proceed with categorical features. An alternative would be to implement PDP which does support categorical features natively.
ALE currently supports numerical features only. An extension to categorical features is possible, but comes with serious caveats for interpretability (see https://compstat-lmu.github.io/iml_methods_limitations/ale-misc.html) so I think some more research needs to be done before investing in categorical feature support.