My understanding of US Mobile’s “Super Carrier” mode a/k/a “Teleportal” is a port between MNO networks is involved. US Mobile considers the port to be internal because the customer remains with US Mobile. Under the hood, however, it’s a standard number port among T-Mobile, Verizon and soon AT&T.
To its credit, US Mobile has built a self-serve interface for initiating the port promising it will be “seamless”. It is, however, not dynamic on-the-fly switching among multiple MNO networks or even the garden variety domestic roaming among DISH native, AT&T and/or T-Mobile coverage offered by the Boosts.
The majority of tech-savvy customers who hang out in US Mobile’s subreddit or other telecom focused forums, for sure. Experience, however, tells me the majority of US Mobile’s estimated 500,000 subs probably don’t know or necessarily need to know which MNO network partner is providing their coverage.
Generally, presuming device compatibility, US Mobile favors its “Warp” (Verizon network) service. Otherwise, “GSM” (T-Mobile network) service is suggested. To their credit, US Mobile SIM kits do include both SIMs. Time will tell how “Darkstar” (AT&T network service) is integrated into this.
In any event, I was more pointing out the inaccuracy of comparing US Mobile’s ability to port between MNO networks (Red Pocket can do the same) to Google Fi’s former proprietary network switching using a single SIM or the Boost’s purported “power of three networks” via domestic roaming.
In theory, any operator (MNO or MVNO) running its own core would be able to offer multi-network coverage. To the best of my knowledge, US Mobile is not actually running its own core. The only MVNOs I’m aware of doing so are Altice (Optimum Mobile) and Mobi (in early beta). In addition to their own cores, direct roaming agreements would be required.
The above said, I do believe there is value in what US Mobile is offering more so with a self-serve interface. If, for example, I was about to travel internationally, I might move US Mobile service from “Warp” to “GSM” because T-Mobile has better international roaming than Verizon in many locations. Upon return home, I could just reverse the network switch.