Startright Motorcycles in Leeds sell the restrictor kits or they will fabricate it for you and make it “official” , just tell them we sent you.
If not, it is possible for your local garage to grab the SV650 kits and try to retrofit them to the Hyosung throttle bodies and give it the “garage stamp” if insurance ever asks for it
But generally I have not heard much about it being an issue riding full power the riders did have A2 but were much much older folk who ride sub 400cc bikes for years , so they just went full whack (yes strange enough I did hear about older riders staying on A2 because they find riding beyond 700cc useless for street use)
For you , you can still make yours A2 compliant , if the Hyosung kits are not there from Startright Motorcycles , then its closest cousin would be the SV650 (Well Hyosung Korea did get involved making the engines or its parts in the past for suzuki) so should make life a bit easier to retrofit some kits.
Really its just restricting the throttle output that’s all!