I'm thankful because it gives me another perspective because I see what I know from my background and not what other people see. The dressage trainer I had was pleased with what she saw. Because for me I like to understand what different people see. So I'm writing this not at any offense because I'm grateful but to explain what I see. I know he tucks behind because that is easier for him, he is built "on the bit" some horses go above the bit, this horse goes behind for similar reason, he goes more behind if I get him more engaged and don't basically throw the reins at him (I lift them up and put them forward for a moment to be like hey dude don't do it). But for me I'm not so worried about him tucking a bit right now because I've seen a lot of young horses do it, not from being pulled there or anyone training them that way but because that is where they want to go and it is easier for them (this is harder to correct than a horse who wants to go above the bit) it takes a while to train them otherwise.
I actually did ride in Germany for a few weeks. But Germans in my experience are very correct, Some are not but some are just beautiful, the best young horse rider I've ever seen was there. Her hands were incredible. But he has a lot of movement and I was taught for medium or eventually extensions to sit a little back to send the energy forward with my hips if I'm having trouble keeping an open hip because it opens the seat and send the horse forward. For example to "collect" I sit a tad forward and lift my hands up and half half the energy generated from his hind legs to get a more "compressed" or collected frame without losing the suppleness of the front end. I'm actually never "pulling or pushing" I never have to really tell him forward, it's more I send the energy up and use his hind legs and balance to put him into the bridle. When I lengthen the reins he still goes for the contact because he is connected from behind, not because I'm holding him there. His balance put him into the bridle, supported with a steady rein connection. For example his natural movement in the long and low is somewhat flat and quarter horse like, where as I'm trying to condition him to carry himself uphill and animated (which is naturally there).
He's 5 and built quite downhill. His butt is 16.2h and his wither is 16h. The canter is a work in progress. His tendency to go downhill is natural, I'm trying to train him so he can carry himself uphill. The strength isn't there. Because he'll have to carry his legs more underneath himself and learn to carry that balance. And a lot of young horses do, Carl Hester in some videos of him riding young horses was saying it is natural for a 5yr old to be on the forehand, that's normal.