Sebastian Snell
Sidephone is Sebastian's only active mobile device. He ported his long-standing number over, uses an unlimited plan, and tethers his laptop to Sidephone when working on the go.
Chris Ristovski
Chris set up a new plan for his Sidephone with a new private number. His smartphone with his long-standing number is kept in a drawer in his office and acts as a filter, forwarding only the most important messages to his Sidephone. Sidephone is what Chris carries daily.
By adding a new number as opposed to switching over his current one, there was no impact to Chris' friends and family (iMessage/RCS maintained - they continue to message the same number).
Summary
Both setups have enabled Chris and Sebastian to keep their total daily mobile phone screen time under an hour. Although their implementations are different, both Chris and Sebastian consider Sidephone to be their primary mobile device.