I understand where you're going with these steps. Getting the window to do this on a prod server isn't always easy.
When I failed-over from Node B to A, the instance of SQL was unable to automatically move back. When I tried to start SQL on Node A I was able to capture lots of information in the Error Log; unfortunately there wasn't a smoking gun in the log. All of my databases started, etc. & then boom. I've been trying to work with Microsoft on this & they seem confounded, too. Also, they seem more interested in the root cause, which I understand.
However, now my boss is on me to get something done ASAP, which I also understand. That's why I wanted to either repair or remove the instance. Since I cannot do either in the recommended way, I need to know what or if there is a work around that doesn't take my databases offline, such as just evicting the node from within failover manager, then rebuilding the server & node from scratch.