It's not that easy to install a 1Password vault onto a new device, so I'm okay with the 2FA codes getting stored in the same place as the passwords and sync between.

The realistic scenerio for my passwords leaking is target database exploitation or MITM attacks and not vault exploitation. The 2FA is still a rolling phrase that makes any capture of my password useless after about 1 minute, and not only that but I actually even get email notifications ('xx logged in from a new device') if someone uses my password but can't get past my 2FA. It feels very secure and I reject the dogma that 2FA means 2 separate physical devices.