Does Windows Server Backup (for Server 2008 R2 and 2012) support taking backups on different/mixed size writable DVD and BD format?

Does Windows Server Backup (for Server 2008 R2 and 2012) support taking backups on different/mixed size writable DVD and BD disc formats?  Or do all backup discs in the backup set need to be exactly the same size?

For example, can you hypothetically create a successful backup, using the following examples:

1. Mixing 100GB and 50GB BD-R discs together, and/or along with 25GB BD-R discs?
2. Mixing DL-DVD+/- R discs with standard-size DVD+/-R discs?
3. etc.

Thanks!  :)