Yes changing those can help and removing the throttle for first backup is a good way.  See this thread for a similar discussion - https://community.veeam.com/discussion-boards-66/veeam-office-365-backup-painfully-slow-1987?tid=1987&fid=66

Thanks. What about removing the throttle completely, or perhaps a script that will remove it every 90 days since it’s a temporary setting in M365? We would like to speed up our incremental backups.

I’m curious to know what others are getting in speed for their incremental backups - just for mailbox backups.

You cannot remove it permanently as it is controlled by Microsoft unfortunately.

One of our previous engineers has set the mailbox job to be backed up every hour. Is this ideal? How often are you backing up the mailbox users?

Once a day.  No reason to me to back up that often. The question is why??

Why should you do this every hour ? Only to keep mails / files in backup that are placed and removed within a regular 24h backup schedule. So you have to think if it’s beneficial to have these files in backup, given the fact these are less important files / mails.

I’ve seen cases with the same frequency and the result was that evey promotional mail / spam / … was taken into backup before the end-user could judge and delete them. This resulted in huge storage cost at no use.

I tend to back up every 8 hours.  But chances are, I don’t need to run it that often.  And as I get more org’s/mailboxes on the server, I may be forced to back that off from 3x a day, but for now that works.