Here is the BIG question: will AMP apply that margin at the instant you place that trade during the trading session, or on your daily statement? Those are two entirely different circumstances. The problem for my clients was that AMP (and other discount brokers) didn't have the risk systems of sufficient capability to correctly margin spreads in real time during the trading session.
If I could make a suggestion; maybe reply that you require further clarification that the SPAN margin credit would be applied the instant the trade is made. Don't take that for granted. I speak from experience.
Crude is also. The Butterflies a bit further out in the curve have some real opportunity. The prompt month calendar pairs are essentially delta directional with the flat price.
SPAN is the daily futures exchange risk calculation procedure for determining the margin credits for spread positions. In other words, it costs much less to margin an exchange recognized spread as compared to flat price outright contracts. Here is an example: https://www.cmegroup.com/trading/en...CL§or=CRUDE+OIL&exchange=NYM&pageNumber=1
AMP does not support exchange-traded spread SPAN margins at this time. You are on the hook for every leg of your spread, at full exchange margin, 5 minutes before the market close. Once the market re-opens at 6 PM, you are back on daytrade margins. Sorry to burst your bubble.