I do monitor message failures, but I don’t use this feature - I forward all bouncebacks to my email and then use Power Automate to put together a daily digest (to detect issues with our DKIM record) and I also have a separate weekly digest that shows how many messages went out successfully:
The bouncebacks do catch misspelled addresses (although I don’t usually take the time to fix them - I have in the past and it just seems never-ending)
I’ve also modified canned reports and I’m happy to take a look (maybe we could just add a filter?? see below?), although I also hear your concern about the subscriptions needing to be changed. I know there’s been advice posted here before about how to modify the .rdls that generate notices - see this post, for instance. I suspect that since the Email_SummaryReport report is in the Notices folder, as long as you place the updated version in the correct folder, it would send the updated list using the same rules it follows now.
