Caetano didn't really decide anything. All they really did was say the three reasons MA cited explicitly conflict with Heller. They sent the case back to MA to determine more appropriate reasons.
I don't see how that would be relevant to this case.
Caetano defined self-defense as core to the 2A. Everyone has ignored that aspect, as Caetano related to stun guns.
Not to mention this nugget in Alito's concurring opinion:
The lower court’s ill treatment of Heller cannot stand.
https://www.supremecourt.gov/opinions/15pdf/14-10078_aplc.pdf