US Mobile outlines their new security features

https://www.usmobile.com/blog/us-mobile-account-security-technical-deep-dive/ US Mobile appears to be a popular American MVNO for people in the privacy space, at least based off GrapheneOS forums. I’m interested to hear your thoughts on their new security features and how it currently compares to other mobile providers. Do you see any glaring privacy or security weaknesses or issues with their announced security features?