Simon 5 is coming soon!
Simon version 5 is currently in beta testing. It is a massive update, introducing a much-requested feature: syncing the Simon data between multiple Macs, plus a Simon Status service, a Link Checker filter, improved Find filter, iMessage and Speak Error notifiers, a new app icon, and much more.
Important: please note that Simon 5 requires a minimum of macOS 10.12 (Sierra), and will be a paid upgrade from Simon 4 after the beta. Purchasers since September 1, 2020 automatically get a version 5 license (that also works in previous versions).
Re: What is a black triangle in the Simon monitor window table?
The black triangle is what that quoted text refers to as the gray triangle — it's actually a dark gray.
What it means is that the test hasn't had a recent change or recovery — probably never changed or failed. If it changes (assuming you have a suitable filter to detect changes), it'll turn bright green, then slowly (over a few months) fade back to dark gray. And similarly for recoveries, but fading from orange.
If you don't want this time-sensitive color coding information, you can change the option in General Prefs to use simple status icons, which just use green for good (success) and red for bad (failure).