While we do not have limits on the number of accounts a trader can have, we do limit the total account value of all accounts held by a person to $600k.
For clarification, during the challenge (Phase-1 and Phase-2), you are not permitted to trade more than $600k. If you trade more than $600k at any given time, then you will be refunded for all of your accounts and you will have to start over.
For example, you can have two $200k accounts and two $100k accounts, which add up to $600k in total account value. However, you cannot then add any more accounts beyond these as the total account value would exceed our $600k total account value limit.