Feels like there's a hole in between 'Entire computer' and 'Volume level backup'.
For users who have multiple internal drives but don't need all of the drives backed up, it would be nice to be able to select backup sources by physical drive rather than just by logical volume. I often work with system that have large dedicated temporary/scratch drives that don't need to be backed up in an 'entire computer' backup job, but we still need a working backup of the system and data drives that could be restored in a bare-metal restore scenario.
If the volumes listed on the "choose volumes" screen were to be presented inside physical drive "containers" in a hierarchical list, users could easily select entire drives for backup or just select specific volumes (as done currently). For boot drives, especially, capturing the volume layout, boot records, and manufacturer's hidden partitions (and anything else required to make a restored drive bootable) would be helpful.
Thanks for your consideration.