Currently, Yasuo is one of the most infuriating opponents (for me, and I'm sure many others). The mechanic of his shield AND his wind-wall both drive me pretty nuts. Using the windwall to deny CS (which shouldn't even be a thing since that is a major anti-fun mechanic - it is one mechanic Riot decided to change from Dota) and then being able to block a counter attack with his phat passive shield removes a lot of counterplay.
I propose combining the two abilities - prevent Yasuo from using Windwall if he does not have his passive up. Once using windwall, his passive will be down.
This gives Yasuo the ability to use both, but not at the same time, while also allowing for more counterplay. Otherwise I suggest removing Yasou's ability to prevent CS with Windwall, only for game health.
Thank you for taking the time to read this!