There's another take-home message in this situation: Removal of a catalytic converter or a crankcase vent breathing system can trigger the anti-tampering law. If you have a motorcycle that originally came with a catalytic converter in the exhaust system, think about that anti-tampering law before you go put a full exhaust system on it ... It hasn't historically seen much enforcement on motorcycles but that doesn't mean they couldn't. (FWIW everything that I own that originally came with a catalytic converter, still has it. I have my doubts that the catalysts on motorcycles are designed for long term durability, I doubt if the one on my zx10r does anything any more, but it's still there ...)
I have a feeling that the non-integral cow bladder style catalytic converters on I-4s probably fare pretty well. The teeny ones on CBR125s and the integral ones that come on Harleys probably don't last very long, and the ones on "sport" v-twins probably fall somewhere in between the two. All bets are off if the bike gets much track use, but in that case pretty much everyone puts on a full exhaust anyway...