1. "Twin Chargers" is irrelevant for Supercharger.
2. "Twin Chargers" comes into play for home 220 use and/or HPWC use.
3. Some (all?) of us think it will naturally be more expensive to install the 2nd charger as an upgrade rather than as part of initial vehicle construction.
About 50% of the public EVSEs in San Luis Obispo, CA are > 30 amps and would benefit from dual chargers!