I don’t ever remember a senior Petty Officer on subs who didn’t start his career there.
Putting senior PO’s in who are not ‘qualified’ is not going to work. There many duties they will not be able to perform for at least a year onboard. Others will have to pull their slack until they get their dolphins.
With that limited range, cannot they just lift their heads and talk with each other directly?
Have you seen the size of this protest ?
As to the technology, it basically turns each phone into a micro ‘well tower’ as long as one of the phones can reach the next, you have comm. through all the phones