Thule/Yakima Roof Cargo Box on Leitner Rack

Hello everyone,

Took the family snowboarding and realized it would be really convenient to use my Thule or Yakima cargo boxes to keep the families gear secured and dry, for this trip I just tossed all their stuff in my Decked drawers.
For subsequent trips I am wanting to mount my roof top cargo box on my Leitner rack, I was not able to find something designed by Leitner but did consider their RTT mounts as a potential solution; aside from that my searching has not produced results (I saw one mounted atop an RTT though).
Wondering if anyone has done this or knows someone that has. Trying to explore solutions that are implemented so I spend less time figuring it out if possible.

Thanks in advance.