Taking the profit, locking in the profit, win/loss limit, you can call it whatever you want. My point is that if a play is a good play ( positive EV and you're bankrolled for it), you should play it until you're tired or run out of time or don't enjoy the game anymore. Your previous results shouldn't be the determining factor.
Let's say I'm playing 10/7 double bonus triple play at Binion's during double points. I have $2000 in my pocket and my time constraints allow me to play for 4 hours. Now, the third hand into the session I get dealt aces for $600. I will keep playing for my 4 hour time constraint. I might lose a thousand in the next 4 hours and I might win a thousand in the next 4 hours. That $600 win on that one hand does not affect the rest of the hands I play. If the play is good before the big hit, it's a good play after the big hit.
When I first started playing long , long ago I used to put a $20 in and that was my session. If I got down to $5 left and then managed to get back to even, I would cash out, happy that my session ended with me being even. Then I would go to another machine and put a $20 in and do it all over again. It didn't take me too long to realize that I was using up a lot of time and effort with no real benefit.
Now, if you believe machines are hot and cold and once you use up the good hands on one machine, it's time to move to another machine or quit for the day, that's fine. But I believed that machines had a preset number of good hands, I'd never drop another coin in one.
If switching machines or setting a win goal makes you feel better, then that's what you should do. I don't think it makes any difference. As long as you are playing a good play and have the bankroll, play as long as you want to.