I don't use cleats as I can generally get it all done with ratchet straps, simply wrapped around the bars. Our racks have very few sharp edges, making it somewhat inviting to grab on anywhere, or put a strap around anywhere, which is one of the appeals. But you knew that.
My only real beef with cleats is that they can get caught on stuff, like my sweatshirt sleeve, etc., and I also don't need to look like a contractor all the time. I've snagged myself with enough welded on cleats on truck ladders racks, enough to swear I'd never do that. But I could probably make a case for a bolt-on option though, for example it wouldn't be too difficult to create a new side gusset with 2 holes so that one could easily bolt on a cleat, and then take it off again. I can look into that if someone would be interested. thanks as always for the great comments!