Of course this does not replace an official answer by the team, but they have said that this is only a problem if you do it systematically. As long as you don’t make all of your trades with the intention of selling them off immediately after, you should be fine.
I’m in the same boat as you, last week’s oil crash took me for a ride, I made 200% profit and then plummeted to margin call within an hour because I underestimated the fluctuations. (All short positions) I’m pretty sure one of the positions closed out within a few seconds of me opening it because it hit my stop loss.
But I made my initial investment back and now I’m using much smaller amounts to trade oil. Expensive lesson learned! 