Hi Rocco, the settings you need depends on the strategy and the portfolio. For example if have a single strategy and it has 5% drawdown on the backtest with 0.1 lot size then if your prop challenge has an allowable 10% drawdown you could trade 0.2 lots. Adding an additional factor of safety anywhere between 1.5-2.5 is sensible also depending on your risk appetite.
If you then combine this strategy with another one to create a portfolio and the portfolio has a drawdown on 2.5% then of course the lot size can be doubled for each EA.
This is how I do things anyway. Hope that makes sense.
It does depend on risk appetite though to some degree