Graal itself still has limitations with many libraries yet, the biggest one being having any library that heavily uses reflection. I'd look at some of the work red hat is doing with some of its java libraries and quarkus: https://developers.redhat.com/blog/2019/03/07/quarkus-next-g...
IIRC you also end up relying on a graal-provided version of python that may or may not be kept up-to-date by a project for which it's just a secondary target. Been there with IronPython and Jython, it's no fun.
