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: Failed ports
Yes, you can configure Simon to only notify after a certain number of consecutive failures. See the Options page of the Notifier.
As to why they are failing, you could look in the Activity log to see what the errors are. Feel free to post here if you can't figure it out (you can't attach screenshots to comments, but you can edit your post to add them), or email me.