Unless you have to take your bike for inspection, get whatever you want and don't even think about it. In the state I live in we're "not allowed" to do anything to the exhaust to make it louder. But we don't have a yearly inspection or have to take the bike to emissions testing (ever). And since you can get bikes from the dealer with a full system installed if you wish, they police can't argue that whatever we do to our bikes isn't stock.
So in my state, we do whatever to our exhaust and there's nothing that be done even though we're "breaking the law."
However, for cars in my state - we need to bring them in for testing every couple years after the first 4 years when bought new. If you tamper with the exhaust without getting everything sorted before emission testing, you'll fail. Still ways around that though with ECU flashes and bypasses to turn check engine lights out for missing 02 sensors.
I had the experience probably 15 years ago now, here in Queensland State, of a Police and Machinery blitz on a very popular biking road one Saturday morning, where the Police checked your licence details and registration, Alco test, then you were made to wait while Machinery Inspectors went over your bike with a fine tooth comb.
Then they did a DB Sound Level Meter test using these wooden set squares so the sound meter was in the right place at the exhaust as per Australian Standard AS83/00 (I think). Basically, set at 90 Deg sideways to the line of the exhaust's body outlet tip and then 1 metre upwards at 45 deg angle.
They read the compliant noise plate, rev the motor to say it's noted as 5000 RPM, and if you fail, it a defect notice and then you have to present it again in 2 weeks at their Test Centre for a re test, and you are not permitted to ride it away.
The joke was on them that day as my bike was so brand new, I had only ridden 15 Km there from the Dealership, but they still insisted on measuring the tyre tread depth with all the rubber tyre tit*s porcupining across the tyre surfaces.
The noise man said my Honda CB1300 was too quiet as it was 5 db under the State limit of 96 DB. He said (seriously),
"Were here to 4 PM, so come back with a hammer and a large screw driver and punch some holes in it till it gets up there and we'll retest it for you as you go about it".
Never saw them again that day or since.