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: Simon Monitor -- sorting and scheduling
Hi.
Regarding your first question, yes, Simon intentionally only does one check at a time. It used to allow any number of checks at once, but this led to the machine getting bogged down when doing too many at once, and even freezing if all the available resources are used up. I added the queue mechanism to address this. However, when there are a lot of tests being checked fairly frequently, this can lead to excessive queuing. I plan to address this either by adding a preference to set how many checks to allow concurrently, or an automatic value.
Or I might just expose a "hidden" preference that's already there. You can disable the queue mechanism entirely by entering the following in Terminal:
defaults write com.dejal.simon2 PreventOverlappingChecks NO
As for the sorting issues, the first one is related to the above. Simon starts due checks by scanning through the list of tests in the current sort order, starting the first due one it encounters. So if it is sorted by Name and you have a large amount of tests, some will never get reached in that scan. The workaround is to sort by the Next Check column, or do the above Terminal command.
Regarding the jumping around of tests when sorted by Service, that is due to the way the sorting works; if the sorted column is equal for some tests, those tests are sorted in effectively random order within that grouping. I might see if I can improve that.