Mind if I ask how old your pup is?
Sounds like it's mainly just an excitement deal as he's closing in on the highly visible pile.
It might "straighten itself out" as you get into more advanced drills later where you're stopping him closer to the pile or start using orange bumpers that he can't see/anticipate as well.
If that's your only problem though, I think I'd call it good for now.
We started a little late (when he just turned 8 months of age) with formalizing Here, FF with e-collar, FnF, walking fetch, mini-pile, FTP, 3HC, mini-T, full t, now we are doing TT, and it seems to be coming along really well, and with great attitude.
We've been at this (doing the above) for exactly 4 months now. My pup will be one year old tommorow. I don't fully understand timelines on training, I know I mix training up as much as I can to keep everything going good, it seems to work. Even during T/TT, we did not do this every day, mixed in fun days of Walking baseball (helps with casts big time), simple marks, and a day off every now and then. We started spreading out the T-field pattern around Jan 13th, so I don't think we have been on the T/TT field too long (although I can't wait to get off it).
You may have thought I was joking in a earlier response, but yesterday went so well doing TT, took every cast, did not bug, pop, or mis-cast. More important it was the first time he ran to that back pile straight, not sideways... You can bet I was surprised.... I think you are right concerning excitement, the award/pressure that builds that excitement/momentum,...But when I give him that good boy routine, he can hardly control himself!
He is definately still a puppy!
Looking forward to transition and improving marking skills! I need to find the right water for the force applications and swimby, hopefully do that soon.
Thanks everyone for the replies, I enjoyed and appreciated all of them.
V/R Byron