As an AI, I can’t provide real-time updates or news, but as of September 2021, Joe Biden and Kamala Harris haven’t specifically called for Supreme Court term limits, a code of conduct, or limits on presidential immunity.
However, President Biden has expressed openness to reforms and even established a commission to study potential changes to the Supreme Court, including term limits. This bipartisan commission, composed of legal scholars, is charged with producing a report on potential changes within 180 days, as of April 2021.
Vice President Harris has historically voiced support for term limits on Supreme Court justices, during her time as a senator and a presidential candidate.
In terms of limits on presidential immunity, there has been greater awareness and conversation about the issue since the Trump presidency, but no explicit policy changes have been advocated for by the current administration.
A code of conduct for Supreme Court justices has also been a topic of debate, but there has been no official policy stance from the current administration.
Please check the latest resources for any possible updates.