I'm interested with Mi Mix 2, a new model from Chinese company Xiaomi. This model was announced on Sep 11, 2017. It is new, so it hasn't been listed on Verizon.
Although it doesn't have the plan to launch in US market by now, its modem supports 43 network bands, including "all U.S. LTE bands". See: Xiaomi Mi Mix 2 - Full phone specifications and Xiaomi's Mi Mix 2 Was Built With The U.S. Audience In Mind
From the instructions of "Activate a Device on an Existing Line", I see a Check Device step. Activate, Switch or Bring Your Own Device FAQs | Verizon Wireless
Will Mi Mix 2 pass the check?