-When the same EA is installed on different brokers the results will be different. This is because the historical data on each broker is somewhat different due to their liquidity, volume of trades, volatility, etc. In addition the spreads are not the same and some brokers will charge a commission on each trades.
– One thing you can do is to test the brokers to see which one performs the best. To do this you can install the same EA on several different brokers demo accounts. Wait one month and see which broker had the most profit. Then use this broker for live trading.
– After passing the funded account it is up to you if you want to change the Lot size. The advantage of reducing the lot size would help keep the account from having a deeper drawdown that could cause you to lose the account. Leaving the lot size the same has the advantage of allowing for higher profits in a shorter period of time. So it depends upon the risk that you want to accept.
– Petko does not have a public demo account. However, I have been demo trading an FTMO EURUSD v4.1 EA since the first of August and I publish my results in the FTMO topic area of the forum. The link is below. As of two weeks ago the account was up 6%. I will be publishing my results up through tomorrow after the market closes tomorrow. It looks like the demo account will show a profit of 9% since the first of August. Also as of Yesterday (Monday) I have started trading this account with a live 10K FTMO challenge. I will be publishing these results twice a month.