It looks to me TST is just looking for every rule in the book to throw traders back to the Combine. If they were really in it for the backing opportunity, they would try to work with the traders, not against them...
I think having the "Additional Rules" for the Junior Trader increases the odds of being sent back to the combine, and thus reduces the financial risk of the backer.
However, if one trades the combine by utilizing these rules, and meets the parameters of the combine to either qualify for a rollover or meets the parameters with the P&L objective, then the transition to a live account won't provide any surprises, since the trader would have already been familiar with the additional rules.
In other words, to improve the chances that you will succeed in the live account, you may as well trade AS IF you were a Junior Trader within the combine.
Then once you are live, the only objective is the profit goal, which has no time limit. For example, the 30k account has a $1,500 profit goal to Senior Trader, the 50k has a 2k goal, and the 100k has a 3k goal.
If a person makes it to Senior Trader, then the additional rules go away. Of course, this is a win-win for both the trader and the backer, since the account would be carrying a positive P&L balance, and that is when you can negotiate greater size and start taking withdrawals.
So as I've posted before, the real question is this:
"Can you trade within the parameters of the Junior Trader with the additional rules such that you can meet the profit goal without ever hitting the daily loss limit and the trailing max drawdown and get to Senior Trader?"
If you can't trade with those rules while you're doing the combine, then you probably won't be able to do it when you're live as a Junior Trader.