I would wait until the right seasonal time for Western Pennsylvania.
Getting water to the roots now though. I’ve poked holes through thickness like you mention with a simple old screwdriver. I would wiggle it through rather than just hammer it through. A long dull pointed screwdriver helped my irrigation…..I had a screwdriver, thin flat tip, where I ground the end down like a knitting needle because the driver handle is easier to work with push in and pulling out.
I can’t see how big, or how small, that plastic pot is but it may be restricting growth for the size of the tree causing the tree to under-develop. My first though was that the tree was actually dug up recently and forced into the smaller plastic container from a larger container or from burlap.
I've also up-potted a pine with a lot of roots without cutting or disturbing the roots much. I select a pot just a bit larger and fill the edge with similar soil/substrate that already exists. You’d still need to poke some holes in the original rootball area…otherwise water will flow to the least resistant sides and your rootball would remain dry. Experts could tell you this is quite risky though.
I guess in a similar scenario, I have a pine in a small flat wooden box which I’m certain is very root bound. It’s been in the box for about 4 years now. The pine seems to enjoy life bound up. Growth is slower. Back budding is frequent. Needles extend but I keep pinching 3/4 of the needles off creating a more compact lower growth. I water the tree daily. I poke holes in the soil each spring when the candles begin to form.
I have full size yard pines that sometimes have slow needle growth years, usually it is a lack of water and hot temperatures. Like we have had around the country this year. If I water well the trees seem to return with growth.
I have not needed it but periodic dunking and resting the pot and all in water can help assure the rootball gets moistened. It’s work but not that bad really. So…Does that rock formation that the pot is sitting in have drainage?
I am not a pine expert though. Hopefully some of the experts will chime in here with their thoughts and experience.