I have the extra crossbeams as well, but that’s because of the width (8’0) still it’s crazy that you standardly get the wider placement on those trailers that are just marginally less wide (same axles).
I worry about the dust insomuch as I worry about a great many other things in horse ownership that are less than ideal but we all pick out poison in this regard. I use just enough fresh shavings plus pine pellets in the pee spot (gelding). The pine pellets are absolutely not blowing around and the newer shavings are not blowing around any more than the hay bag full of hay! And while I’m not worried about hay in front of the horse for local trips, we average about 20 7+ hour trips a year, so hay will be blowing around. For the long hauls I clean out the trailer each time because we stage out of the trailer. The bedding just goes in the stall and I set aside some new stuff to go in the trailer on the way home.
My feed dealer got in some of that airlite bedding that is dust free and I’ve seen it in action, it totally is. It’s also too expensive and annoying to use in stalls, but a few bags a season may be just perfect for the trailer. I’ve got two away trips in September that I may use for a test run.