Drivingtenacity good job on finding a technique that works for you!
I don't think you have to worry about reinforcing negative behaviors with this technique, for several reasons:
1. You are bringing out the food BEFORE she gets wound up and goes over the top. So the negative behavior is being "cut off" before it begins (great!)
2. You say her name first, then she turns and looks at you, and THEN you reward her. Therefore, you are rewarding her for focusing on you in times of stress, which is exactly the right thing to do!!
3. Through relentless repetition, the good thing (the food) becomes classically conditioned to the behavior and the situation, which means that she will gradually associate seeing other dogs with the opportunity to get the food. The critical thing, which you are doing excellently, is using extremely high-value food so that it overrides her discomfort with the situation (since you are catching her before her stress level escalates), so new positive associations can be formed since you are making the situation have a positive and enjoyable outcome for her.
And also, simply
preventing her from going into reactive mode in the first place is the most important thing that you're doing because every time the dog does go into full blown reactive mode, the more ingrained that pattern of behavior becomes. So what you are doing is great! keep up the good work!
I did and still do the exact same thing with my dog. It used to be that if we saw strangers walking in our direction we would have to cross the street or he would see their direct approach as a threat and fixate on them then bark and lunge at them as they got close. Using this technique, I was able to gradually get him used to focusing on me instead of on them so that we can calmly walk past strangers without him fixating on them and winding himself up. From doing it a lot, he has now started to ignore some types of strangers on his so we can still pass them by but without me needing to demand his attention on me anymore.
