A lovely vibrant tree. I'd prune away those 3-4 lower branches, they
are stealing strength from the tree and preventing it from growing
taller. If not regularly pruned crabapple trees become a bush. Mark
those branches with a ribbon and remove them after the leaf fall at
the end of the growing season. Use a sharp pruning saw. First make a
cut on the lower portion of each branch to prevent striping the bark
when making the top cut. Spray the final cuts with sealent from a
plant nursery. You can use those branches for smoking meat. If you
don't smoke meat give them to someone who does... it'd be a shame to
turn them into compost.