I think most people register them out of state for this reason - Minnesota and Arkansas being the two go-to (also for bypassing vehicle road-readiness inspections...).
I really wish it was tailpipe based. I liked the PA emissions laws where you could improve the efficiency of your vehicle and it would pass. Not so in CA, must be numbers matching and CARB certified parts/combo.
They used to do it that way. Still do, for some cars, although the pre-ODBII set is now out of smog regs in most states.
Turns out the tailpipe breather machines are finicky and difficult to calibrate, causing false positives and false negatives (sometimes corruptly).