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: Option for multiple failures before Notification
Hmm, I can see how that could be useful in some situations, but I think the UI complexity cost would outweigh the benefits. Especially since it isn't too hard to duplicate a notifier and tweak it.
One planned change that will help the situation where you need to subsequently edit two notifiers will be the ability to select them and edit both at once — this will be particularly useful for things like adding the same notifier to lots of tests at once. I'll probably add that sometime next year, once I complete the move to Core Data-based storage.