I'm going to chime in with my 2 cents from the peanut gallery.
I suspect that if you have the stock cat, then the MP215 or similar stage 1 style tune is about as good as you're going to get. It's a very docile around-town tune (as you know), but does add some scoot under WOT.
In a state that requires legit SMOG testing like CA, you can't really get around that stock cat.
The MR230 tune seems to want the higher volume/velocity output exhaust offered by an aftermarket cat. I can't comment on any other tunes. However, I believe the MR230 tune suppresses a "ready" signal fault or something (sorry, I'm sure you and others know better what specifically is being done). As a result, the car won't pass emissions tests (whether or not it actually is in violation of CARB emissions thresholds).
I guess that if you're willing to swap the cats back and forth as needed, then you could (as you are doing) overwrite the tunes as needed as well -- putting the CARB-compliant MP215 tune in there every N period of time just before the test and then swapping both tune and cat back after.
I have all the MP215 hardware, the FMIC, the mountune induction hose, their replacement cat, a replacement lower charge pipe, and the MR230 upgraded tune. The car is very well mannered around town but clearly accelerates more assertively (and throughout a higher RPM range) vs. the prior setup. That's what you'd expect since it's a tune that's about adding and holding torque at a higher RPM (so handy for on-track corner exit).
If I had to test every other year, I'd probably would have stuck with the MP215. The cat is a kind of a PITA to get in and out so I would not be the one to do it (translation: more service $$$).
YMMV.