...but wouldn't it be sensible to apply for an out of state CCW license? Yes, I know CA doesn't do this. It could be a way to challenge their CCW laws without violating any law (constitutional or not).
Because CA does not have a provision to license non-residents, they can't apply. If you can't apply because you aren't a state resident, then it's much more difficult to raise a discrimination case.
I suspect we'll see some real oddities and uneven treatement with the laws in the next few years as new decisions change the landscape.