Why don't i see any Thule or Yakima boxes on Overland rigs?

That is the sort of road Yakima approves of, and the kind we often drive as well. We also often travel the following, and they told me these roads are too rough for their boxes. Sad!

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Based upon Byways issues with the Yakima roof box I emailed them to see if they had any other boxes that might work for these same types of roads I drive down to my fly fishing/camping rivers here in Michigan and they said not at this time. Might there be any boxes out there that I could "bolt" to the cross bars on my Highlander, or secure a 2 x 4 (or 6) on the bars and use that to secure a box to? The larger Pelican boxes would be great but I'd hate to drill a few holes in an expensive box. Also, the Yakima/Thule etc. are streamlined for travel and I couldn't locate anything online that might fit the bill. It would have to be lockable as I'd be tossing in lightweight camping items along with boots & waders.
Thanks for any suggestions.
https://www.yakima.com/showcase-20 I’m looking at a showcase 20, anyone have one?

How do you all store them when not in use?
Mine is just leaning against the wall in my warehouse. It's a PITA to put anywhere but the perfect place for the tent, chairs, and stuff like that. I have the largest Thule box. It's long enough that I can put 7ft fishing rods inside which is really nice.