If you're a resident, they eventually have to let you in. But if you aren't, they can reject you for any reason. This isn't something you can solve with tech. Those of us who are citizens of the US need to vote for politicians who make privacy a priority, and be more politically active in general. I feel like you could even make the play that it's bad for business, because it's impeding business travel. You could even point to this very post as evidence that many companies consider it a Big Deal - the idea that they have to explicitly hide their company secrets in this way because border agents are out of control.

Not CBP though, which is the relevant institution for international border crossings.

web login is likely the same as app login credentials. I don't use 1password, but that's the generate case with LastPass (at least last time i used its mobile app).

So, if they take the actual password, as opposed to having you log in for them, then they can easily go to 1password's web interface.

I'm not sure if there is a legal barrier to taking that step, but there is no real barrier there if the credentials are the same.

Perhaps if there were also travel credentials, that would be useful. With the travel creds there would be no indication that you were in travel mode and no access to additional data.

There is an additional key/identifier that you don’t have to carry with you that would prevent them from logging in even if you had to give them your vault password.

They already ask for social media account logins.