How can we minimize the swaying of high decks without
adding x-bracing. The x-bracing is in the way. The decks
consist of wood members. The posts are 4x6.
1. Add 2X flat diagonal bracing under the deck joists, nailed to the underside of the joists, or
2. Add 2X diagonal flush blocking with metal strapping over, nailed to blocking and joists.
Either way has worked well for me in the past. No worries.
Another way is for the deck is to be covered with plywood, then the plywood serves as a cantilever floor diaphragm. But this is obviously not feasible unless the deck is waterproof.
you could also beef up the connections at the beams and posts to be more rigid. also make the perimeter beams bigger and lag bolted to the posts. i've built a 15'x25' deck about 12 feet off the ground independent of the house and the thing is solid as a rock. relied on doubled up 2x10's around the perimeter and another in the middle. lag bolted all the connections to 4x6 posts. ran decking at 45 degrees. made sure to have blocking at appropriate locations to stiffen the thing along the joist spans. we used a few small diagonal braces but near the tops of the posts and they're completely out of the way so that you can go under the deck.