At week 3 of flower, yes, I'd remove them. Thin lower branches that sit in the shade and stay weak usually only make small popcorn buds, and they take energy from the top colas. Cut them cleanly at the base with sterile scissors, and do it in one session now, not later, because after week 3-4 the plant is no longer in the stretch and healing takes longer. Don't remove thick healthy branches or too many leaves at once. If a thin branch is already near the light and has good bud sites, you can keep it and support it with a soft tie. A rule of thumb: cut anything below the point where the canopy gets enough light, since it will not catch up in the remaining weeks