Prune them just before bud break. Yes a plant can only produce so much sugar, pruning should make the berries sweeter, and bigger too. It’s hard to do. I also remove weak canes and leave the strongest, and best spaced canes.
That is conventional wisdom, you can leave them too, and decide what work best for you.
No you’re doing it as most suggest, you can limit laterals to one or two feet too. You can prune primocanes anytime while growing and even the next year before bud break. In the middle of winter is not the best time as dissication can be an issue with uncut canes, and more so with fresh wounds