Thanks for the compliments.
So the next consideration is that after you lift or lower the rack, and have provisioned for the changing elevator spread, you'll need to be able to lock the slides at all 4 points from being able to move forward or back when in transport. Otherwise the rack will not be sound especially when off road or in high speed accident avoidance maneuvers.
Next is we have to address how this rack will absorb the kinetic energy produced on the left to right axis. If the rack vertical beams are rigid like when steel is used, your rack will destroy your trailers cargo bed or at a minimum crack all the welds. Read this, "When you need to elevate the rack to accommodate ATV's or Motorcycles, it's easiest performed with 2 people. Pull all 4 retaining pins, unlock the racks rear left and right Linear Bearing brakes. Elevate the rear end first, then have a helper insert the pins at the desired height. Repeat for the front end while standing on the storage cabinet lid. Remember to retighten the Linear Bearing Brakes.
I find standing on the tailgate is best when elevating the rear and lift from the center of the racks cross bar. Stand on the Storage Cabinets lid when doing the front end. If you are by yourself, a small scissor jack and piece of wood works great to lift each end.
If you elevate the rack to its maximum height, we recommend cross-strapping one end of the tray to the exterior tie downs as shown in this image-set. You want the rack to have a little sway left to right when carrying a heavy load like a Roof Top Tent, Awning, and additional cargo. The rack systems Elevator Beams have been engineered to provide that. Ensure that if you need to cross strap, only do one end of the rack.
The sway we've engineered into the elevator system relieves the left-to-right axis kinetic energy caused when off-roading on severe terrain or when cornering at high speed. The slight bowing the beams provide is necessary so that those forces don't break the rack or trailer, which is common with rigid welded assemblies.
The Elevating Rack System provides support for payloads up to 1000 LBS. However, we do not support traveling with that much weight on the rack as it will raise your center of gravity and create a dangerous hazard. Keep it at a maximum of 400 LBS when in motion.
And If you are going pack that much weight overhead, ensure you top off the water tanks. This will provide a 200LB counter balance at axil height".
Can you attach an image of how you have mounted your vertical elevator tubes to the trailer?