NB - Interesting
I used to trade longer term trends in stocks that way.
With day trading(where you plan to be out by the end anyway) I find it feels more complicated. If you get into a move and then get a 2nd entry signal, fine.
But otherwise , what is to say that if you enter your 2nd lot when the 1st lot is in profit that it isn't going to turn around and hit your original stop, giving you a larger loss ?
Eg you buy half at 70, stop 60, you buy the other half as it goes to say 75, so 60 still the stop with a higher average price. In my experience moving stops early or to a technicaly insignificant place is pointless, feels good at the time but makes you miss lots of moves.
We've opened up a can of worms, many ways to skin a cat and all that 🙂