Per Smartsheet documentation (and experience), If you have an automation that runs on multiple rows, all rows will be grouped into one email notification. I don't have a problem with this. However, it overrides your Custom Subject line for the notification to a generic default:
I understand that this would occur if you were referring to individual fields for the records, but when fields are not in the subject, it should not change. An alert is not always a "Reminder".
My request is to maintain the custom subject line in automations.