Way I view it, there are three problems to consider.
The first dilemma is replacing the gun after a defensive incident. Given California's political climate, it is probable once the gun has been taken into custody by police for evidence, it will not be released to the owner again. Unless said owner spends more money then the gun is worth on lawyer fees to petition for a court order mandating release of the weapon-and even then, the gun grudgingly returned by the police won't be in the same condition it was surrendered in. That can pose a problem if acquiring the SSE was logistically difficult &/or expensive; should Sacramento outlaw SSE, replacing an off roster handgun legally will be nearly impossible in that event.
Problem #2 is civil court. There's little legal weight in trying to slander a defender in criminal court for using an off roster handgun, especially when LE does so quite frequently in California. The trouble is in the civil suit afterwards filed by the ventilated scumbag's family, where only a "preponderance of evidence" is needed for a finding of wrongful death. This is the biggest threat we face IMO as armed citizens: because it emotionally and financially blows to hand over all your worldly assets and livelihood to the family of the scumbag who tried to kill you. Any step we can take to avoid the horrifying prospect of paying a wrongful death judgement to the dead perp's baby momma should be considered.
Problem #3 is perception by the issuing authorities/police. Unfortunately government employees are not the sharpest tools in the shed when it comes to real-world firearm knowledge. Most people-including ones who work in CCW approval offices- think that if a gun isn't listed on a "Safe Handgun Roster", there's a good reason why that is. Since these bureaucrats are the ones determining if you can exercise a "state issued privilege" to keep and bear arms, it may be wiser to not rock the boat on the subject to ensure an already illegal and discriminatory CCW issuance process doesn't get any more antagonistic then it needs to be.
The more prohibitions you have, the less virtuous people will be.
The more subsidies you have, the less self reliant people will be.
-Lao-Tzu, Tau Te Ching. 479 BCE
The 1911 may have been in wars for 100 years, but Masetro Bartolomeo Beretta was arming the world 400 years before John Browning was ever a wet dream.