Maximum number of emails for Send alert flow step

I haven't heard/read/encountered the maximum number of email addresses users could add in the Send Alert email's flow step. We usually end up creating a distribution list as soon as there are more than a certain number of email recipients that need to be sent alerts. You can also use custom/lead tokens to house the email addresses (multiple email addresses need to be added in the comma-separated format), and then reference that respective token in the Send Alert flow step so you don't have to re-add the list of emails at all places.

Text token: {{my.Internal Alert Distro}}
Value = email1@example.com, email2@example.com, email3@example.com 

Just a note that this will only work with the trigger campaigns, for the batch campaign you'd have to employ a workaround by using the Request Campaign flow step and have the alert campaign trigger on the Campaign is Requested trigger.