TS> WHY is there any need for a new packet format?
There isn't and wasn't.
TS> Other than the lack of zone (or even 5D) information, what are TS> the points?
It depends totally on the bossnode. I have successfully sent the type 2 pkts from a point to a suitable bossnode that knows what it's doing. If anything the pktHeader - no matter which type - acts more like drag on systems rather than providing any useable data worth the effort of extracting it. There are much better ways methinks.