To add to your list here is what I have found:
SharePoint Rules - Things I've Learned
- You can only have up to 10 email addresses per rule.
- You can only have up to 15 rules per library or list.
- While it looks like you can set a rule for a document in a library, the rule will apply to the entire library. i.e. if you are trying to set up a rule to notify you when a document changes, the rule will notify you when any document in that library changes.
- You can set up a rule to notify you when an item changes and select a specific column to check. You can also set up criteria for that column. Then you can be notified only if the column changes and the change matches the criteria, i.e. set up the rule to check if documents are modified by someone other than you.
- You cannot select a column with criteria to notify you if when documents with that criteria are modified (notify me when documents with a Status of Closed are modified)
- You cannot specify the frequency of the email notifications like you could with Alerts. With Alerts you could select a Summary option and choose which day of the week and time of day to receive Alerts.
While I still like the Rules, especially the ease of maintenance, I'm hoping that they will incorporate some of the functionality they had with Alerts such as being able to set up a Rule at the document level without needing to create a workflow using Power Automate.
Not to mention needing Edit permissions to create these rules.