The baseline performance would be whatever a set of mice would do in the same situation. What constitutes an "unrelated" task is quite a difficult question, we would probably need to iterate a lot on that. If we are to have "hidden" tasks available we need to come up with a lot of new task formulations/variations anyway.

I think that replicating mouse-level adaptability in an intelligent agent while allowing 'inherited' behavioral traits will already be an achievement. And probably take us quite a while.