If you want to enhance the Performance you can do the Re-Buys with a Martingale Factor of 2 or more but I don't recommend to do this!
Martingale for ReBuy = 2*(OldPosition Size).
Let the old Long positions opened even if trend will go down and make every rebuy as showed in the chart! It should be possible to take out a Profit with this one but trade carefully and gently! Don't force the TP take the BreakEven if you have to make a Re-Buy!