or you can always make new chat tabs, that something i have always done, i have 5 chat tabs.
Main - normal spam in here but no trade or l4g
Trade - Just trade or L4G, so i only see it when i looking for somthing
Group - Party and raid
Guild - Guild and a guild healer chan
/w = Any /w get poped in here
This way i can just look at my main, i can see all i need to see in a raid or soloing or anything, the only time i need to use the tabs is if i missed a message, but the /w tab does flash for a few secs after getting a /w.
Only time i miss a /w is when i AFK for focusing for long times (ie bosses)
So no addon needed