@mmckerns, would you be up for adding a feature to dill that allows forcing a particular class to be serialized by value rather than by reference? Specifying byref=False only applies to a limited set of cases at the moment.

The specific motivation is pulumi/pulumi#7453, in which it is desired to have the pickled class always serialized by value, regardless of whether it is in __main__ or a different module.

cloudpickle recently added a feature that allows this sort of control: cloudpipe/cloudpickle#417. (But there are other reasons that cloudpickle doesn't work for Pulumi.)