I have the whole set as well as the 22/23 regular Blacktips. I only sailed 3.4, 4.0, 4.2 and 4.5 TEs so far. The TE feels a bit lighter physically in particular in the top, and it seems they prefer a bit less downhaul, although the regular BT's too can be sailed with a relatively tight leech and the TE's still handle a bit more downhaul when needed. The TE's feel a bit fuller and I'm pretty sure they generate more power when rigged for it. Many of my around 10 session in total with the TE's ended in underpowered sailing and I have ben VERY impressed how much speed and glide you get out from them. I had this underpowered 4.2 session when everyone else was on 4.5, 4.7 and 5.0. I had a small high rockered board too and still got around better than most. Still no problems whatsoever at the top end. All these things are things the regular BT is good at already. But it is like the TE is even more Blacktippy, so to say.
So far I think pretty much the same sizes, with some possible +-1 liter change here and there. Then (probably) an addition of a 106 or therabouts. In this stage of prototyping we also look at some tail length adjustments, shorter on some (78+84+92, biggest change on the 78) and longer on the 99. The 106 will have a tail like the new 99. Then some very small rocker adjustments. I'm also adjusting the rocker along the rail in the tail, ie increasing it to add some additional looseness. Inspired from some of my personal shapes I then run a different double concave flow with a deeper concave in the tail which give a bit of extra projection out of the turns. Not all of this is confirmed yet in testing but it is the current stage of development.