Box Squat vs. parallel PL squat/Stretch reflex
About a month ago I began box squatting after predominantly front squatting for about a 5 weeks or so. I did this because of a low/mid back injury that caused pain whenever I bent forward, even at the hips, and the front squats kept my back straight. I felt that box squatting also reduced this strain on my back. I managed to use 260lbs for 12 reps on slightly below parallel box for a final set on 5/3/1 and I even had some left in the tank. My question is before I begin parallel squatting without the box, should my weight increase of decrease as opposed to box squats? I've heard that without the box the weight used should increase because of the stretch reflex, but I don't really feel any sort of stretch reflex when I do a standard PL squat. I can ATG squat barefoot without any butt wink so I'm quite flexible. Could this have something to do with my lack of a pronounced stretch reflex? Or am I just overestimating its effect?
Thanks for the help!