USGFX is definitely a Market Maker, this is why they have the restriction in their PDS that all trades must be over 180 seconds (i.e. 3 mins), anything less than that they consider fraud. So if you have an account with lots of trades under this amount you will never get withdrawal of profits. Their PDS also states 'We MAY choose to limit our exposure to our clients by entering into opposite transactions with hedging counterparties as principal in the wholesale market. However, there is also a risk that a hedging counterparty that we deal with may become insolvent. Where this occurs, we may not have recourse to underlying assets and will become an unsecured creditor of the hedging counterparty' Whenever a PDS uses words like MAY you know they are a B book Market Maker, they aren't promising to pass on 100% of trades like Global Prime would.
Therefore I also suspect that even if this EA is modified to only close trades after 3 mins, it's unlikely the broker will let you trade there for long, as you win they lose, so eventually you will get a notification you are no longer welcome. However happy to be proved wrong in the long term if users of the system want to weigh in and talk about their medium - long term results.