Cryptomator as part of a 3-2-1 backup strategy

I’m interested in using Cryptomator as part of my 3-2-1 backup strategy, and I would like to solicit feedback from this community to know if I’m using Cryptomator correctly. Thanks in advance for your help!

I’m setting up a home server running Ubuntu. It will have 3 partitions: 1) OS and services like Nextcloud; 2) NFS for nightly backup of User 1’s MacBook; and 3) another NFS for nightly backup of User 2’s MacBook.

I will have 2 external HDDs attached to the server. Drive 1 is for daily backups of all 3 partitions of the internal SSD, and Drive 2 is for weekly backups of the SSD.

All 3 drives (1 internal SSD and 2 external HDDs) will have full disk encryption. The purpose is to protect my local data in case of physical theft. I’m not sure if I need additional privacy / security protections for this local setup.

I want to include an off-site backup in my 3-2-1 backup strategy. This is where Cryptomator might come in. I’m thinking to use 3 Cryptomator Vaults on Drive 1 (the daily backup drive) such that each of the 3 partitions on the SSD are backed up to their own Vault. Then, each Vault would sync to a cloud service account. My goal in using Cryptomator Vaults is to keep my data private while stored on the cloud service. Drive 2 (the weekly backup drive) won’t sync to cloud; it’s just another local backup in case Drive 1 fails.

Please let me know if this setup makes sense, technically, as well as in terms of my goals: a) having an offsite backup; and b) keeping my data private while on the cloud server.

In addition, if Cryptomator makes sense for this approach, does it still make sense if the 3 Cryptomator Vaults grow to very large sizes, such as 1 TB in size? Or is it better to come up with some strategy to use Cryptomator with many small vaults?

Thanks again!