Thanks for your comment/question. 3D secure is helpful and would be redundant. We found that 3D secure support is a bit nebulous across platforms and also dependent upon the implementation. (Javascript vs API vs your ecommerce platform.)
UpUp also lets ecommerce teams verify customers without requiring their engineering teams to immediately implement 3D secure.
We do expect we'll end up using 3D secure as part of our flow in the future.
Especially when the card providers move the risk, and therefore part of the cost of the transaction onto the bank. It's up to the bank to make 3D Secure, secure by authenticating the user in it's own way.