As the minimum trading days for a Stellar 2-Step Challenge is 5 days for each Phase with no time limit that’s why you have to maintain 5 minimum trading days on each Phase even if you reach the profit target earlier.
If you can reach the 8% profit target in your Stellar 2-Step Phase 1 within 5 days by complying with all the rules, then you will be eligible for a Stellar 2-Step Phase 2 account.
The same thing applies to the Stellar 2-Step Phase 2 Challenge as well. If you can reach the 5% profit target in your Stellar 2-Step Phase 2 Challenge within 5 days by complying with all the rules, then you will be eligible for a FundedNext account.