Hey there @shipping,
From double checking our knowledge base article, I confirmed that the shipment dimensions are not a field that can be directly exported. With that in mind, a potential alternative could be to use the Shipment - Package Type field and use your known sizes for those boxes. While I know this isn't precisely what you are looking for, maybe it can help?
If anyone else has any work flows that work well for them, please share them below!
From Moderator Davis, May the force be with you!
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