Mine also will light all the bars when in traffic, never has flashed, but sub-conciously it registers in my brain as "Hot....That can't be good" Guess you have to just not worry, just that it is an "on or off" deal with no way of gauging the exact temp it's at in between. I'd prefer a small numerical gauge....
I might look into fitting something by spring. I'll also flush the coolant and fill will "Engine Ice" I use it in my Laverda, the temp gauge registers a little less than when the "green gold" was in there, and never climbs high enough to worry, even in stop-n-go traffic.