I’m not sure how easy it would be to implement it, but imagine having Siri shortcuts…
“Hey Siri, switch my card to Amex”
“Hey Siri, how much have I spent today”
Then, imagine the shortcuts (using the Shortcuts app) you could build, you could make a shortcut that knows you’re going travelling, so switches card
I second this. Curve just needs to share that data with Siri then users will be able to create these shortcuts.
Please add support for Siri shortcuts to be able to quickly switch between cards. This would be very handy
MOD NOTE: switched to Ideas category to allow voting
Hey @mainnine
Welcome to the Community! 
I’ll be forwarding your suggestion onto our product team. We really value it, so please do keep it coming!
I really hate Siri, but any possible was to make easier to change among cards would be welcome.