Splice have to be implemented.
But we need to figure out how to make it more convenient for python programmer point of view.

Server crashes when calling a stored function from python client.
But it's not crashes when calling a function from the command line client. It seems RequestCall forms some "packet of death" and python client has a defect (as well as the server).

If Response instanse will have attribute that contains the time spent on each request, it will be possible to collect some statistics over many requests.

It is possible to pass a list (or mapping) of index names when creating Space instance.
In this case in Space.select() the index can be specified by its name.

user = server.space(0, named_index={"username":1})
user.select("root", index="username")

PEP-0249 proposing to implement exceptions as attributes of Connection class:

All exception classes defined by the DB API standard should be
exposed on the Connection objects as attributes (in addition
to being available at module scope).

These attributes simplify error handling in multi-connection
environments.