I am a bit confused that this is even still working.  The answer is simply NO.  The reasons have been explained in a variety of ways.  It can cause dangerous driver actions, and just because it is not an actual convoy, it is still NOT allowed.  Plan and if need have meeting spots to regroup.  Know where you are going if driving; do not expect to just "follow".  How often does it need to be said?  

The best method we have found is rally points along the way.  We all depart at the same time and maybe meet at some designated break spot, then meet at the next logical point. For our winter trip this past January departed the CO, met about an hour down the road (got outside the major city we live near), then another hour to our first trip stop.  We departed there a few hours later and the meetup was an hour down the road for the camping spot. On heading home day met an hour down the road for a tour stop at a historic place, then an hour or so up the road and after we hit the main highway, stopped at a large center with a beaver as a mascot.  Then the 1.5 hours home to the CO.   At the designated stops keep up with everyone, also we have a text group for trips and have our co-pilots handle the exchanges If our camping spot is more remote, off the path, we meet as close to there as possible on the way in, then convoy the last few miles.

I'm with you! The ventilation and being able to transfer the weight onto the hips is huge. I have two external frame packs and I'm not getting rid of them at any price! My old, smaller pack for my scout, the larger volume one for me. The soft packs were originally for climbers and it made sense for them, but I'm not a climber, I'm a hiker.

Which means they would have to exceed the legal limit?

Saw the driver ahead of you rush an intersection and get t-boned, and I never set convoy again. We arrange rendezvous points. The scout riding shotgun navigates for me. (I have paper maps for the very purpose.) He also checks my texts while my car is rolling.