The smallest—but most effective—change would be to put a time limit on prorogation in an effort to eventually establish a new use, a new convention. I don't have enough time to tell you about all the small, but sophisticated, reforms that could be made to the conventions. Nevertheless, putting a time limit on how long Parliament can be prorogued is probably the best way to ensure the government still has access to prorogation, while reducing potential harmful effects.
On February 18th, 2021. See this statement in context.