In general, I would say that changing rules should be avoided. I don't think changing the rule would enhance safety, but actually make it worse as the plays people are used to making would be dramatically changed.

Also, if you sail lots of different boats, or types of events, it's nice to have consistency in the rules. Trying to keep track of changing rules would be unnecessarily difficult.

As an umpire, one of the most difficult things, IMHO, is to make the switch from Match Race to Team Race mode (each have modified rules), especially when events are close together.