This is confusing me what you're saying. Once a player is 20 years old, training slows down. Once he reaches his cap, it will either train really slowly, or just stop. DMI is how well your player trained the past week. If its over his regular, he was trained. Game shape will make this increase too, since he got a good amount of minutes.
That's not right. Yes, training influences the DMI, but ONLY because the DMI is determined by the player's skills which of course change when he receives training. But the game shape changes the DMI a lot lot lot more than pure training does.
The only occasion you can take the DMI to judge whether a player was trained or not is when his game shape doesn't change at all during the training update. And that doesn't happen too often...
PS: There's a reason why the "M" in DMI stands for "meaningless"
We have both said a lot of things that you are going to regret.