I set mine up for the five-second flash, then steady....... otherwise you stop somewhere with traffic sitting behind you and the flashing lights would prolly give them the ****s.... particularly other riders you may be travelling with. (And THEY will let you know about it at the next coffee break!!)
OK so you reckon that's good...!!
It's like riding in front of a bloke who's got his headlight modulators on.... it's a real PITA....
If you have stopped and you see someone coming up behind you, you only have to release then re-apply the brake to make 'em flash again.