Defoliate?

I would remove that lower growth that’s gonna be stagnant air like organoman said it’s high risk for issues down the road. You’ve got a great canopy up top - I’d personally concentrate on that area and remove all the lower stuff that’s not getting light either, and will get even less when the budding begins - it will likely be dark under there in a few weeks time. You never know until you try things a few different ways and figure out what works for you but I would be worried about stagnant air/lack of air flow and lack of light in that lower middle area if you leave it as is