Hey everyone - We have an old 1920s house, and the covered front porch decking was looking pretty rough. I sanded down what I could, primed, and put a coat on Ben Moore Porch and Floor paint on it.

The paint ended up bubbling up in a few places, which could have been because it was 85F when I painted it down. It also could have been a few areas I didn't prep properly.
The new paint on there however has really made clear how rough the wood surface is - clean paint, slightly glossy will do that!!
What I have found is that the boards are bowed - across the board. The edges of the tongue and groove are higher than the middle bit of the board - which means when sanding the higher edges were getting way more sanding.
There is also a lot of pitting and dings in the wood, that are now showing up because of the clean paint.
What would people recommend for me to renovate this properly? I am thinking that I really need to sand it down properly, maybe with commercial floor sander - to get the edges level with the middle of the boards.

But this is going to be a lot of work. I also don't see how I can do this under the railings, and the board ends that are on the other side of the railings.
Is there also a filler that I can use to fill the dings and rough sections and make this look better?
In person it looks worse than the photos.