No, the $0.84 are correct, but your objection is justified. PnL calculation is not really difficult, but there are many factors involved.

For spread, rollover, and conversion from price differences to profit, the current broker's parameters are used, not the historic rates. The reason behind that is that you want to use a developed system today, at current rates, and not in the past. So the simulation does not really simulate history, it simulates the present, but with a history price curve. For the conversion from asset price differences to account money, the broker publishes a value named "PipCost" or similar on his website. This value is used for the conversion. It changes from time to time when the counter currency and the account currency are different.

You can find details about the account simulation in the manual under "Data import/export". There are about 10 parameters per asset that determine how PnL is calculated. You can set up different parameters for emulating different accounts, also in US-$, so you then won't have the conversion issue.