Nikola tesla is a forgotten genius, and people know that Edison is far better than him.
In a sense, Edison is better at discovering the market, managing, applying, mastering and obtaining patents, and making money from patents (from a social and moral point of view, the light bulb was invented by Swann, a British electrical engineer, but he applied for a patent very late, and Edison was just a shameful imitator who skillfully used the market to promote it and came from behind).
Yes, nikola tesla is a person like Swan. They pay more attention to the real technology and science, while ignoring the real market and other factors. They are real scientific people, which makes them easily forgotten by the times, or even forgotten forever.
In this way, your question about "what to threaten him with" seems insignificant, because people who think that he attaches so much importance to science will not care about external things. When people are easily threatened, even the stupidest excuses threaten them.
Furthermore, I don't think he compromised at all. It is inevitable that he did this in order that his invention could be used by more people.