In accordance with Case ID: #04944933 and the quote from your Customer Support Engineer:
"You can also submit such requests on our forums at https://forums.veeam.com by creating a topic marked as Feature Request and stating the desired change. Our Product Management Team is actively engaged in the forums and would be happy to discuss your request, and be able to comment on it further."
Feature request: Add VCC Repository Support with O365 Backup (and thus support for tenants with performance & capacity tiers with immutable storage) OR add the same object storage options within the O365 Backup as are available in the SOBR extend bucket options in VCC (see below).
Short summary about myself/our company and why I opened the case:
We're a Private/Public Cloud & Modern Workplace Provider/Integrator with our own infrastructure (5+ Datacenters) in Switzerland as well as O365/Azure infrastructure. We are also running three publicly presented Veeam Cloud Repositories in three datacenters with an additional Amazon S3C Cloudian storage tier in a fourth datacenter for archiving/compliance needs with buckets per tenant attached as capacity tiers within the SOBR extends.
Problem:
We are managing customers with O365 workloads (including backup) and thanks to the ever increasing ransomware cases many of them are starting to look at immutable backups - that's where we have the problem with Veeam Backup for O365.
Now to the case (mostly copy/paste from the Case ID - sorry if some of it is redundant

###startcasecorrespondance
Goal: O365 Backup to VCC Repository target with our Cloudian S3C archive tier (in a SOBR extend) for immutable backup storage.
Problem: O365 Backup can backup directly to Cloudian S3C but you can NOT set the same options within O365 as you can in the VCC tenant (copy to archive tier for 30 days immutable, retain local data for x days, move data if more than 90% local repository is full).
Question: How can we implement O365 backup with VCC tenant repository targets?
After some back and forth I added some further details:
Question 1: Are there any plans to support repositories other than local or object storage in the near future for O365?
Question 2: Will there be options to configure immutable backup properties like it already exists on Scale-Out Backup Repositories (SOBR) for object storage repositories within Veeam Backup for O365?
Details (this is not supported on O365):
In the properties of the object storage repository itself (under Bucket) you can define "Make recent backups immutable for: xx days". That's the key feature we are looking for with our O365 Backups.
While the following is an absolute must have - In addition to the above I can set age-out policies to handle the redundant dataset between local and S3 repo – also not supported by O365):
In the properties the SOBR extend under capacity tier you can I can set the object storage (in our case an S3c Cloudian Appliance) and define properties like "Copy backups to object storage as soon as they are created" as well as "move backups to object storage as they age out of the operational restore window" in order to have only a couple days of the data local and the rest on the object storage (instead of having two copies of everything for the whole retention time)
In the end our customer requirements are pretty straight forward:
Customer wants O365 Backup solution from us with xx days immutable.
While we can backup O365 to our S3c Object Storage (Cloudian) just fine we have no way to make that backed up data immutable right now from the O365 Backup. On the other hand we can do this perfectly fine with our Scale-out Repositories on our VCC Backends (with the same Cloudian S3C). So in the end I ‘know’ Veeam knows how to do this – but simply didn’t built in the feature into the O365 Object Storage part.
In the end it’s rather simple – If we can’t use Veeam we will have to move to another Backup Vendor or Technology because for some of our customers immutable backups (whether it be Hyper-V/VMware or O365) is the deciding factor.
###endcasecorrespondance
Looking forward to some feedback on this - or others who the same problem (and maybe solved it some other way?)
BR,
Andre