Do others here use Wordfence? Wordfence Central doesn't work with the Seedprod Coming Soon plugin though

I’d say the coming soon module re-routes site requests to a certain page. I’ve seen things like this in the past where coming soon type plugins return the ‘coming soon’ page in  API requests and break things there, so this is no surprise.

As for WordFence, I really enjoy their blog posts of new vulnerabilities and how they work. I think they offer some pretty good piece of mind tools for free. While I tend to agree with @Mr David,where services should be on the correct layer, 90% of WP blog owners are on shared hosting - where clients are often able to make service level decisions. In these cases, a service like WordFence (or any application level security) is your only option.
Alternatively, you should ask your host about whether they offer services that WordFence do, for peace of mind and education.

I tend to prefer to keep security outside of the site code itself. Keep services on the correct layer, I believe. I have also found WordFence (admittedly older versions) to be resource intensive at scale. A WAF is generally my first port of call