There is a video on YouTube that shows a carbon akra on an MT-09 WITH a catalytic converter, so it should be possible for the MT-07.
There are test stations here in Australia (and likely in most countries) that can test your exhaust for dB and emissions and issue you a report stating compliance, so just because the manufacturer/seller says it is not road legal doesn't mean you can't get it tested yourself to comply. The akra is connected with springs, so fitting/removing the catalytic converter for road/track use should be straight forward. The baffle is also removable so you could have another one made up if the stock one is still too noisy for road use. In Australia you must stay less than 5dB above the stock dB, which for my bike is 90dB at 4000rpm, to stay legal.