Q: Professional reputation damage control (Cease & desist letter? To who/what company? Better options?)

A: It's also a huge city which is actually very small. Professionals rarely have time to ruin other professionals' lives. They also don't want to give some law firm ammunition for a lawsuit. Remember, it's a one-party consent state to record others so I assume that I am being recorded on every telephone conference although that's unlikely. Remain professional. Never post or talk negatively about a former employer or colleague and they unlikely will about you. Obtain professional references in advance from people who are willing to give them to you. If your "business practices" differed from your employer's that's understandable. However, if you mention a "botched proposal" of a former employer that is unlikely to go over well since your employer owned the business and you owed a duty of loyalty to it regardless of its competence. That's correct, the common law Master Servant Doctrine is very much alive in New York and it sounds like you would have been the latter in that equation.

You describe a "poor fit" with this particular employer which any prospective employer will understand. It's so common in the legal industry that all of us get it. And the COVID experience, I suspect, will bring many law firms to recognize that the entire legal industry needs to change; now. I could go on and on about how many lawyers I have worked with over the years who I perceived as having many faults. But I never do because it's a tough profession, a hard way to earn a living, and talking badly about lawyers serves no purpose at any time. Your best course of action might be to move on without dwelling on anyone's faults. "Evidently given" does not sound tortious which would require an intentional, malicious motivation to interfere with prospective employment nor would any court likely consider it a "plausible theory" for discrimination.