Thanks for the feedback @BramVanroy
There are a few things here indeed and I think the first is that we should rationalize more the logging of the library.
For instance these Set __getitem__(key) output type to torch logs are too much information for the users, in particular since they are actually only used internally by the library in these calls.
Now the fact that you have to use the method in a specific order seems to be a bug, if you want to open an issue about we would be happy to investigate.