John Ladasky wrote:

The guide suggested pretty standard pruning cuts -- eliminating the
long vertical suckers, interior crossing branches, and branches growing
downward; selecting well-spaced side branches with good angles between
them; and, modest heading-back of the branches you do keep. As for the
shape, an "open center" configuration was recommended. This means that
after the main trunk branches, there is no central leader. Supposedly
this lets light/air/pollen/pollinators into the center of the tree,
resulting in more fruit.

I'd certainly take out the central boughs. Do it on a frost morning.
See if anyone locally wants the apple for turning. It's excellent for
that. Aim to keep the boughs that permit the easy use of a ladder.

If I had kids, that tree would be a tree-house by now.