, group riders are definitely briefed on how to execute maneuvers. Large groups in formation simply require a lot more advance signaling to ensure safety and smooth execution. Hand signals are also used to supplement the awareness.
Multi-lane highway lane changes take extra time to relay the turn signal all the way back and then give tail gunner time to secure the lane for a coordinated simultaneous group action.
Passing via oncoming lane is easier, with each bike passing separately and responsible for their own safely executed pass as conditions permit.
Right and left turns take extra time primarily for safety to account for diverted attention. As group leader, being in the left track of a staggered formation, I specifically watch for the rider immediately behind me in the right track to repeat my blinker and hand signal when making a right turn because they will run me smooth over if they weren't paying attention. I have actually had to abort a right hand turn because the rider clearly hadn't noticed my intent to turn. Had I simply assumed, well you can guess the probable disaster. I have found that I usually need 2 full cycles of the blinker before turning. I've had to get in the habit of hitting the blinker every 5 seconds or so to keep it active.
I admit, when I'm not in a group I generally give about three blinks before initiating my action. Sometimes more if situation warrants extra caution. Sometimes less if nobody is in striking range.
I realize most K1600 riders aren't in big coordinated groups riding in formation, so I figured my perspective on blinker usage would add some interesting insight into other usage scenarios.