Since you are specifically talking about the Reserve Business card it's important to note that after $150k in spend, all additional spending results in 1.5x miles per dollar. I understand you don't need any more miles, just stating it for anyone that's reading and is more like me.

My wife and I fly a lot and are extremely flexible with our flight times and dates. I find all kinds of ways to maximize the use of miles combined with booking very far out flights so when we get the inevitable schedule change I can easily move us into far more desirable, (and far more expensive) times and routes at no additional cost. This results in much better value out of our SkyMiles.

Beyond that, for you, I'd just spend the $75k for unlimited club access and then move to a different card.