The lollipop should be done before switching to flowering; however, if you see that the plant doesn't have space to develop, then I would do the lollipop during flowering. In your case, from what I see, I think you have space, so I wouldn't stress the plant. If you see that it's bothering the others, go ahead and do it, your decision based on my advice, whatever you think is best. I see it with good color, it's fattening up; I do see a little bit of yellowing at the bottom, but it's super slight. If you want it to get better color, give it a bit of nitrogen. Overall, it's looking great, you're doing a good job, happy growing! 💨💨