So I was using ChromeDriver 2.40 which worked great with OpenFin 10.66.41.18 or Chromium 66.0.3359.181 if you prefer.
However after upgrading to latest OpenFin stable version (11.69.42.29), I started getting an error denoting version mismatch between ChromeDriver and Chromium: Chrome version must be >= 66.0.3359.181
Fair enough, I thought and downloaded Chromedriver 2.44 which is the closest I can get to v69, still getting an error: Chrome version must be >= 69.0.3497.0
So, close but no cigar as OpenFin now runs on Chromium 69.0.3497.128
But that means we reached a dead end completely losing the ability to automate OpenFin as if you get the next available ChromeDriver (so 2.45) you get an error that chrome: Chrome version must be between 70 and 73
In other words, latest stable version of OpenFin is not supported with a matching ChromeDriver. Just raising this in case anyone else is experiencing the same issue.