How does that work? I'm not familiar with Ray, but I'm assuming you might be referring to actors [1]? Isn't that basically the same idea as multiprocessing's Managers [2], which also allow client processes to manipulate a remote object through message-passing? (See also DCOM.)
According to the docs, those shared memory objects have significant limitations: they are immutable and only support numpy arrays (or must be deserialized).
[1] https://docs.ray.io/en/latest/ray-core/walkthrough.html#call...
[2] https://docs.python.org/3/library/multiprocessing.html#manag...