Good question, from what I have seen some clubs race Saturday, some do not. Pros and Cons to each way I suppose and would depend on each racer for preference. For me, I have one bike I am still fine tuning and need all the practice sessions I can get on it, so I appreciate practice days. Thankfully I do have a ready to race bike as well, so two race days would be cool too. I would agree with you on racing both days, if we had separate test and tune weekends. Typically rule change discussions take place at the end of the season at the AGM.