Immutable Backups and retention with incremental forward forever

[BRogers]

Dear team,

I just set up my first direct S3 backup to Backblaze with object lock.
It is set to incremental forever by default.
Just to be sure:
If I have set 15 days immutable, but keep 30 versions in the backup job (incremental forever), does Veeam still ensure that the required blocks/data for the last 15 versions are kept immutable, even if they are older than that?

Thanks for your help.