At Collabshpere, HCL Lifetime Ambassador, Daniel Nashed presented on Domino 12 Backup and Restored and outlined additional way's to improve backup times. If you haven't seen the presentation, please find the time to review it, it's excellent.
Simply put, one of the easiest ways to improve backup times is to Optimize the size of your NSF files before you do a backup.
Smaller NSF = quicker backup.
Features you can utilize are:
1. Design Note Compression
2. Document Compression
3. Attachment Compression
4. Implementing DAOS
5. Implementing NIFNSF
6. Move Full Text Indexes to a different disk
7. Using DBMT
And in our opinion the easiest way to implement these options is to use The Domino Optimizer.
Here are some of the settings:
It does it all, and much more. So why not check it out for yourself with a free trial https://www.preemptive.com.au/optiimizer/