Within the span of tagging the boss once and refreshing my browser, the previous set of raids is usually still the same, meaning it'd only help if I want to run something else that was up, which it doesn't really help since I'm rarely seeing any event ragnaroks in the first place, as I mentioned. However, that's pointless for me regardless as I have two windows with the same account open so I can see what other help requests are up and run another raid while my other window is running a separate raid.