Only teleporting 1 person in the fireteam during the timestream event is not a lag issue - it is a code issue. It is literally the game choosing 1 person when the design intends for 3. The "fixed" this before when they made the decision by the game random instead of the people furthest back - they could fix this one as well but choose not to because such a design ruins a run rather than help it. If they start banning people for cheesing Crota, then what about all the people who cheesed the Templar, or Atheon?