When I search the forum for Incremental, I see posts from a decade ago, mentioning the intent to develop this option.
Is there still a chance this may be available sometime?

Speaking from expererience managing VAX VMS systems, incremental backups are both a blessing and a curse.
A blessing in that they reduce the time taken (and storage required) to make backups and a curse in that you need to have the original backup and (all) the incrementals to restore a system and a restore is a slow painful process.

Luckily incremental backups shouldn't be required now that computers are so much quicker and storage is much larger/cheaper.

I don't find MS takes too long to perform a backup but that might not be the case for you.
Personally, I use the companion and Windows to make MS backups from my Android tablet. This has the advantage that the most recent backup is on a separate system (in case something happens to the tablet)

I really hope that Mike doesn't spend any time investigating incremental backups; when something goes wrong, you just want a simple method of fixing it without finding that you only have part of the solution.

Have you investigated Synching to keep your database in step with a second copy. Please note that this is not a backup; just two copies of the same files (making changes in one may impact the contents in the other whereas a backup is a permanent duplicate until you decide it is no longer required).

Geoff

The library synchronization feature has really replaced whatever goal I had with the incremental backups. Incremental backups would just present so many problems, because I can't update the existing backup file as it's a binary file that is packed with data. I'd basically require lots of little backup files and each file would be processed in order, basically replacing part of the library each time. It's generally so fast to create a new local backup file, and it's only when uploading the file to the cloud that it takes a long time. If you are going to do that, you might as well use the cloud-based synchronization instead. At some point I want to update the library synchronization to optionally include settings, so it could function as a replacement of a backup file. 

On a side note, I also plan to support synchronizing to local folders or network shares, which ensures data is backed up but doesn't take as long as a cloud service.

Mike