Assuming you have the front fender on, I think the fender is adequate to stabilize the forks. I've ran the superbrace and have noticed essentially Zero discernable difference, and actually ended up selling it. some people swear by them but personally I think the braces are snake oil.

A new SuperBrace is, IIRC, around $180.00. Did I Believe the T-KAT made a noticeable difference? Yep. Others, some of whom have long histories of riding and pushing in twisties and say Mehhh,, notsomuch,, I wonder if their skills, being smooth, not inputting flex, is why they don't feel the need for a brace. I tend to play around as close to my Edge of the Envelope as I can. If you're going to push your limits, I'd say get one. If you're just going to gently roll through the turns,, then no.

The above entry is an opinion, not to be conflated with Truth,etched in stone.
It's truly a YMMV kinda thing.

If I get aggressive on the street it is not due to intention!  My performance envelope is small and I want to stay in the middle of it. If a brace will keep me there it would be worth the price.