I had this same exact startup idea as well after having issues with customs brokers and all the stupid faxing, bond issues, freight issues, etc. Its incredibly archaic.

I actually did try to use Flexport really early on for one shipment and it was very buggy and basically a total disaster, had to abort and use my old broker. They seem like they're a smart team and they'll get it right though.

I think "re-inventing global trade" is a bit of hyperbolic marketing speak, but in regards to re-inventing customs brokerage they are in the best position to solve this problem because the founder Ryan Petersen is a co-founder of import genius. Therefore they have an incredible database of importers to market their brokerage services to.

And that database and expertise is why I abandoned that business plan :)