yes and even the manufactures are confused about their ratings.
TailgateÂ® Storage Systems
The above link shows 150 lbs on the fold down that looks just like mine. And after they stated that the spare rack was a FR add on, you can see the spare on the lippert website.
The conversation I had with them indicated that the weak point is the frame but as you can see in the photos the frame has a long weld compared to the corner of the rack.
You can see that the one you have that shows 450lbs is in the top photo but I cannot find it on any lippert product listing.. weird.
I am done worrying about the limits and will be happy to just get the 98 lb inverter to ride smoothly and stay in place. The spare can set right next to it on top instead of bouncing at the end of it.
I do wish I had yours though. wanna trade?