Regarding EA usage, you can use any EA (Expert Advisor) as long as we don't see multiple users executing the same trades/strategy. We limit one strategy per user, so if we see multiple users utilize the same EA, it may lead to the termination of your account. So even though the use of third-party EA is allowed, we recommend that each user use their own programmed EA.
Next, be aware of other limits, such as :
Max ticket size (most symbols): 50 lots
Max ticket size (XAUUSD/gold): 20 lots
Open-order cap at time: 100 (active pendings + open positions)
Server requests per day: 2000 (order place/cancel/modify, TP/SL edits, etc.)
Max positions per day: 2000 (per account)
E8 Markets does not limit or restrict a user’s trading style or strategy so long as (1) the user is trading within the rules of the SimFi environment, (2) the user’s trades could be executed in a real market.